Therapeutic agents for neurodegenerative diseases

ABSTRACT

The present disclosure provides for treating neurodegenerative diseases comprising administering acetyl-leucine or a pharmaceutically acceptable salt thereof.

This application claims priority benefit to UK 1613829.9, filed August11, 2016, UK 1702551.1, filed Feb. 16, 2017, UK 1705766.2, filed Apr.10, 2017, and UK 1706867.7, filed Apr. 28, 2017; all of which areincorporated herein by reference in their entirety.

Neurodegenerative diseases are those that affect neurons. Thedegenerative process can involve the progressive loss of neuronalstructure, the progressive loss of neuronal function, or progressiveneuron cell death. Such progressive neurodegeneration often results inphysical disability and mental deterioration. Many neurodegenerativediseases are severely progressive and unremitting, and there are few, ifany, curative treatments.

Although the process of neurodegeneration is not fully understood,therapeutic agents that are shown to be broadly neuroprotective arethought to be applicable to neurodegenerative diseases generally. Inaddition, many neurodegenerative diseases are associated with lysosomaldysfunction. This includes both neurodegenerative lysosomal storagedisorders (LSDs) and many other neurodegenerative diseases, such asAlzheimer's disease and Parkinson's disease, where links to lysosomaldefects have been suggested.

The present disclosure addresses a need to develop improved and widelyapplicable treatments for neurodegenerative diseases. In particular, thepresent disclosure describes acetyl-leucine for treating aneurodegenerative disease or one or more symptoms of a neurodegenerativedisease in a subject. The neurodegenerative disease may, but need not,be associated with lysosomal dysfunction.

In one embodiment, there is disclosed acetyl-leucine, or apharmaceutically acceptable salt thereof, for use in a method oftreating a neurodegenerative disease or one or more symptoms associatedwith a neurodegenerative disease in a subject in need thereof, whereinthe neurodegenerative disease is not cerebellar ataxia or Niemann-Picktype C disease.

In one embodiment of the present disclosure, acetyl-leucine, or apharmaceutically acceptable salt thereof, is disclosed for use in amethod of treating a neurodegenerative disease in a subject in needthereof, wherein the subject is asymptomatic.

In another embodiment, there is disclosed acetyl-leucine, or apharmaceutically acceptable salt thereof, for use in a method ofdelaying onset of a neurodegenerative disease or one or more symptoms ofa neurodegenerative disease that would otherwise be expected to manifestaccording to typical disease progression.

In a further embodiment, the present disclosure includes acetyl-leucine,or a pharmaceutically acceptable salt thereof, for use in a method oftreating a neurodegenerative disease or one or more symptoms associatedwith a neurodegenerative disease in a subject in need thereof, whereinthe method comprises administering a therapeutically effective amount ofthe acetyl-leucine to the subject in need thereof for a duration chosenfrom at least about 3 months, at least about 6 months, at least about 1year, at least about 2 years, and at least about 5 years.

In one embodiment, the present disclosure describes acetyl-leucine, or apharmaceutically acceptable salt thereof, for use in a method ofdelaying progression of a neurodegenerative disease or one or moresymptoms associated with a neurodegenerative disease over time ascompared to typical disease progression, wherein the method comprisesadministering a therapeutically effective amount of the acetyl-leucineto the subject in need thereof for a duration chosen from at least about3 months, at least about 6 months, at least about 1 year, at least about2 years, and at least about 5 years.

In a further embodiment, acetyl-leucine, or a pharmaceuticallyacceptable salt thereof, is disclosed for use in a method of reversingprogression of a neurodegenerative disease or one or more symptomsassociated with a neurodegenerative disease over time, wherein themethod comprises administering a therapeutically effective amount of theacetyl-leucine to the subject in need thereof for a duration chosen fromat least about 3 months, at least about 6 months, at least about 1 year,at least about 2 years, and at least about 5 years.

In another embodiment, acetyl-leucine, or a pharmaceutically acceptablesalt thereof, is disclosed for use in a method of improving in a subjectin need thereof a biochemical marker of a neurodegenerative disease overtime, wherein the method comprises administering a therapeuticallyeffective amount of the acetyl-leucine to the subject in need thereoffor a duration chosen from at least about 3 months, at least about 6months, at least about 1 year, at least about 2 years, and at leastabout 5 years.

In another embodiment, the present disclosure includes acetyl-leucine,or a pharmaceutically acceptable salt thereof, for use in a method ofreducing the severity of a neurodegenerative disease or reducing theseverity of or eliminating one or more existing symptoms associated witha neurodegenerative disease in a subject in need thereof, wherein theneurodegenerative disease is not cerebellar ataxia or Niemann-Pick TypeC.

In a further embodiment, the present disclosure includes acetyl-leucine,or a pharmaceutically acceptable salt thereof, for use in a method ofproviding neuroprotection in a subject having, suspected of having, orat risk of having a neurodegenerative disease, wherein the methodcomprises administering a therapeutically effective amount of theacetyl-leucine to the subject for a duration chosen from at least about3 months, at least about 6 months, at least about 1 year, at least about2 years, and at least about 5 years.

Additional embodiments of the present disclosure include,acetyl-leucine, or a pharmaceutically acceptable salt thereof, for usein a method of delaying progression of a neurodegenerative disease or alysosomal storage disorder (LSD) in a subject. In another embodiment,acetyl-leucine, or a pharmaceutically acceptable salt thereof, for usein a method of providing neuroprotection in a subject having aneurodegenerative disease or a LSD. In an embodiment, the acetyl-leucineis in racemate form, in an enantiomeric excess of the L-enantiomer or inan enantiomeric excess of the D-enantiomer. In another embodiment, themethods further comprise administering the acetyl-leucine in a dose ofbetween 1.5 g and 10 g per day. Further still, in an embodiment, themethods further comprise administering the acetyl-leucine for atreatment duration of two weeks or more. For example, the methodscomprise administering the acetyl-leucine, or a pharmaceuticallyacceptable salt thereof, before the onset of a symptom of the disease ordisorder to be treated. Yet in an additional embodiment, the methodsfurther comprise administering another therapy or agent intended toprevent or treat the disease or disorder to be treated. In an embodimentof the present disclosure provides for a kit for delaying progression ofa neurodegenerative disease or a LSD in a subject, the kit comprising ameans for diagnosing or prognosing a neurodegenerative disease or a LSD,and acetyl-leucine or a pharmaceutically acceptable salt thereof. Forexample, the kit comprises a means for diagnosing or prognosing aneurodegenerative disease or a LSD, and acetyl-leucine or apharmaceutically acceptable salt thereof. In a further embodiment of thepresent disclosure, it provides for use of acetyl-leucine, or apharmaceutically acceptable salt thereof, as a neuroprotective agent ina subject having a neurodegenerative disease or a LSD. In a furtherembodiment of the methods, the kits, or the uses, the neurodegenerativedisease is associated with defects in lysosomal storage. In anembodiment of the methods, the kits, or the uses, the neurodegenerativedisease is alcoholism, Alexander's disease, Alper's disease, Alzheimer'sDisease, amyotrophic lateral sclerosis (ALS), ataxia telangiectasia,neuronal ceroid lipofuscinoses, Batten disease, bovine spongiformencephalopathy (BSE), Canavan disease, cerebral palsy, Cockaynesyndrome, corticobasal degeneration, Creutzfeldt-Jakob disease,frontotemporal lobar degeneration, Huntington's disease, HIV-associateddementia, Kennedy's disease, Lewy body dementia, neuroborreliosis,Machado-Joseph disease, multiple system atrophy, multiple sclerosis,multiple sulfatase deficiency, mucolipidoses, narcolepsy, Niemann Pickdisease, Parkinson's Disease, Pick's disease, Pompe disease, primarylateral sclerosis, prion diseases, progressive supranuclear palsy,Refsum's disease, Schilder's disease, subacute combined degeneration ofspinal cord secondary to pernicious anaemia,Spielmeyer-Vogt-Sjogren-Batten disease, spinocerebellar ataxia, spinalmuscular atrophy, Steele-Richardson-Olszewski disease, or Tabesdorsalis. In a further embodiment of the methods, the kits, or the uses,the LSD is Niemann-Pick Type C (NPC1 and/or NPC2 defect),Smith-Lemli-Opitz Syndrome (SLOS), an inborn error of cholesterolsynthesis, Tangier disease, Pelizaeus-Merzbacher disease, a neuronalceroid lipofuscinosis, a primary glycosphingolipidosis, Farber diseaseor multiple sulphatase deficiency. For example, in the methods, thekits, or the uses, the primary glycosphingolipidosis is Gaucher disease,Fabry disease, GM1 gangliosidosis, GM2 gangliosidosis, Krabbe disease ormetachromatic leukodystrophy (MLD). Further for example, in the methods,the kits, or the uses, the LSD is NPC, Tay-Sachs disease, Sandhoffdisease, GM1 gangliosidosis, Fabry disease, a neurodegenerativemucopolysaccharidosis, MPS I, MPS IH, MPS IS, MPS II, MPS III, MPS IIIA,MPS IIIB, MPS IIIC, MPS HID, MPS, IV, MPS IV A, MPS IV B, MPS VI, MPSVII, MPS IX, a disease with secondary lysosomal involvement, SLOS, orTangier disease. In an additional embodiment of the methods, the kits,or the uses, the neurodegenerative disease is cerebellar ataxia, NiemannPick disease, parkinsonism, neuronopathic Gaucher disease, Sandhoff sdisease, Louis-Barr syndrome, Alzheimer's disease, Parkinson's disease,multiple systems atrophy, fronto-temporal dementia or lower bodyParkinson's syndrome. In still a further embodiment of the methods, thekits or the uses, the neurodegenerative disease is Niemann Pick disease,Niemann Pick type C, Niemann Pick type A, Tay-Sachs disease, Sandhoff sdisease, amyotrophic lateral sclerosis (ALS), multisystemic atrophycerebellar type (MSA-C), fronto-temporal dementia with parkinsonism,corticobasal-degeneration-syndrome, progressive supranuclear palsy orcerebellar downbeat nystagmus. In an embodiment of the methods, thekits, or the uses, the LSD is Niemann Pick disease, Niemann Pick type C,Niemann Pick type A, Tay-Sachs disease, Sandhoff s disease ormucolipidosis type II.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 shows photographs of treated (FIG. 1A) and untreated (FIG. 1B)Npc1^(−/−) mice at nine weeks of age.

FIGS. 2A and 2B show weight data for Npc1^(−/−) mice compared towild-type (Npc1^(+/+)) mice, with and without acetyl-DL-leucinetreatment from weaning.

FIGS. 3A-3G show gait analysis data for Npc1^(−/−) mice compared towild-type (Npc1^(+/+)) mice, with and without acetyl-DL-leucinetreatment from weaning. For example, diagonal support, cadence and stepsequence data are shown in FIG. 3A-3C, respectively. FIGS. 3D and 3Eshow front paw (FP) data (stand mean and step cycle in panel D; dutycycle in panel E). FIG. 3F and 3G show hind paw (HP) data (stand meanand step cycle in panel F; duty cycle in panel G).

FIGS. 4A-4H show motor function analysis data for Npc1^(−/−) micecompared to wild-type (Npc1^(+/+)) mice, with and withoutacetyl-DL-leucine treatment from weaning. Centre rearing, activity,rearing and front to back (FR) count are shown in FIG. 4A-4D,respectively. Active time, mobile time, rearing time and total manualrearing count are shown in FIG. 4E-4H, respectively.

FIG. 5 shows that treatment with acetyl-DL-leucine (0.1 g/kg from 3weeks of age) is associated with a small but statistically significantincrease in lifespan in the Npc1^(−/−) mouse.

FIGS. 6A and 6B shows the reduction of lysosomal volume in non-neuronalNPC cells following treatment with acetyl-DL-leucine. FIGS. 6C-6H showthe effect of treatment with acetyl-DL-Leucine on lysosomal volume inNPA, MLII, MPS IIIB, Aspartylglucosaminuria, MLIIIA, and MPS VII patientfibroblasts, respectively.

FIG. 7A shows a survival curve representing mortality in untreated oracetyl-leucine-treated wild-type and Sandhoff mice. FIG. 7B shows barcrossing scores for untreated and acetyl-leucine-treated Sandhoff modelmice. FIG. 7C shows the step cycle time for untreated andacetyl-leucine-treated Sandhoff mice assessed at 12 weeks of age.

FIGS. 8A-8C show the effect of treatment with acetyl-DL-leucine onglycosphingolipid (GSL) levels in GM2 gangliosidoses patient fibroblasts(Tay-Sachs disease, Sandhoff disease, and AB variant of Tay-Sachsdisease, respectively).

FIG. 9 shows a gait analysis matrix for a 75 year-old male patientdiagnosed with corticobasal-degeneration-syndrome before and duringtreatment with acetyl-leucine, wherein fewer pink areas in the matrixindicate improvement compared to before treatment.

FIGS. 10A and 10B show the effect of treatment with acetyl-DL-leucineover time on the overall clinical severity score (CSS) and overallannual severity increment score (ASIS), respectively, of ten NPCpatients.

FIGS. 11A-11J show the effect of treatment with acetyl-DL-leucine overtime on the CSS subscores for each of the ten NPC patients.

FIGS. 12A and 12B show the effect of treating wild type Npc1^(−/−) micewith acetyl-DL-leucine on levels of amyloid precursor protein C-terminalfragments (APP-CTFs) and levels of microtubule-associated protein1A/1B-light chain 3-phosphatidylethanolamine conjugate (LC3-II),respectively.

FIGS. 13A-13C show that after treatment with acetyl-DL-leucine, apatient who had been diagnosed with downbeat nystagmus syndrome couldpartially suppress the nystagmus by visual fixation.

Description

Acetyl-leucine in racemate form (acetyl-DL-leucine) and salts of thesame are effective in the treatment of vertigo of various origins,notably Meniere's vertigo and vertigo of inflammatory (vestibularneuritis) or toxic origin. For example, acetyl-leucine is marketed byPierre Fabre Medicament in racemate form as an anti-vertigo medicamentunder the name Tanganil®. Clinical results of Tanganil® reported byvarious authors demonstrate an improvement in vertigo symptomology inmore than 95% of cases, including the disappearance of vertigo attacks.

Acetyl-DL-leucine has been used in France to treat acute vertigo since1957 and has an excellent safety profile, but its long-term safety inchronic use has not been determined. Despite numerous hypotheses,including stabilisation of membrane potential, its pharmacological andelectrophysiological modes of action remain unclear. (Vibert et al.(2001) Eur J Neurosci; 13(4): 735-48; Ferber-Viart et al. (2009) AudiolNeurootol; 14(1): 17-25). A FDG-μPET study in a rat model of an acuteunilateral labyrinthectomy (Zwergal et al. (2016) Brain Struct Funct;221(1): 159-70) showed a significant effect of an L-enantiomer,N-acetyl-L-leucine, on postural compensation by activation of thevestibulo-cerebellum and a deactivation of the posterolateral thalamus(Gunther et al. (2015) PLoS One; 10(3): e0120891). The symptomaticimprovement of cerebellar ataxia using acetyl-DL-leucine was shown in acase series with cerebellar patients (Strupp et al. (2013) J Neurol;260(10): 2556-61). Another case series did not find benefit (Pelz et al.(2015) J Neurol; 262(5): 1373-5). Quantitative gait analysis showed thatacetyl-DL-leucine improved temporal gait variability in patients withcerebellar ataxia (Schniepp et al. (2015) Cerebellum; 3:8). In aone-month study involving 12 patients with Niemann-Pick Type C (NPC),symptomatic improvement of ataxia was shown (Bremova et al. (2015)Neurology; 85(16): 1368-75). Further, a PET study in patients withataxia given acetyl-DL-leucine demonstrated an increased metabolism inthe midbrain and lower brainstem in responders (Becker-Bense et al.(2015) Abstract EAN).

Acetyl-leucine, however, is not known to treat neurodegenerativediseases, which generally progress over the course of years to decades.The present disclosure surprisingly shows that acetyl-leucine, or apharmaceutically acceptable salt of the same, can be used in a method oftreating a neurodegenerative disease in a subject in need thereof, forexample, by delaying onset of a neurodegenerative disease or one or moresymptoms of a neurodegenerative disease that would otherwise be expectedto manifest according to typical disease progression, and/or by delayingor reversing progression of a neurodegenerative disease or one or moresymptoms of a neurodegenerative disease, such as over long durations, ascompared to typical disease progression. These exemplary uses accordingto the present disclosure, as well as others described herein, wereentirely unexpected, as such benefits had not been observed, and couldnot have been deduced, from the prior art teaching. As evidenced by theExamples, which demonstrate effectiveness over a wide range ofneurodegenerative diseases, the inventors believe that acetyl-leucine isacting as a neuroprotective agent and so inhibiting theneurodegeneration that would otherwise be expected to manifest. Inaddition, many neurodegenerative diseases are associated with defects inlysosomal storage, and, lysosomal dysfunction, such as aberrantly highlevels of lysosomal storage, may be a cause of neuronal dysfunction anddeath. As evidenced by the Examples, but without wishing to be bound byany specific theory, the present inventors discovered, inter alia, thatacetyl-leucine can improve cellular dysfunction (e.g., by reducinglysosomal volumes towards control values) and provide neuroprotection.

Consequently, the present disclosure provides acetyl-leucine, or apharmaceutically acceptable salt of the same, for use in a method oftreating a neurodegenerative disease or one or more symptoms of aneurodegenerative disease in a subject in need thereof.

A “subject”, as used herein, may be a vertebrate, mammal or domesticanimal. Hence, compositions according to the disclosure may be used totreat any mammal, for example livestock (e.g. a horse, cow, sheep orpig), pets (e.g. a cat, dog, rabbit or guinea pig), a laboratory animal(e.g. a mouse or rat), or may be used in other veterinary applications.In one embodiment, the subject is a human being.

“Neurodegenerative disease”, as used herein, refers to any disorder thataffects neurons and involves the progressive loss of neuronal structure,the progressive loss of neuronal function, or progressive neuron celldeath.

As used herein, the singular forms “a,” “an,” and “the” include pluralreference. The terms “approximately” and “about” mean to be nearly thesame as a referenced number or value including an acceptable degree oferror for the quantity measured given the nature or precision of themeasurements.

As used herein, the terms “approximately” and “about” should begenerally understood to encompass ±20% of a specified amount, frequencyor value. Numerical quantities given herein are approximate unlessstated otherwise, meaning that term “about” or “approximately” can beinferred when not expressly stated.

The terms “administer,” “administration,” or “administering” as usedherein refer to (1) providing, giving, dosing and/or prescribing byeither a health practitioner or his authorized agent or under hisdirection a composition according to the disclosure, and (2) puttinginto, taking or consuming by the patient or person himself or herself, acomposition according to the disclosure.

References to “acetyl-leucine” throughout include pharmaceuticallyacceptable salts of the same, even if not expressly stated.

The acetyl-leucine may be in racemic form, which means that the compoundcomprises about equal amounts of enantiomers. Alternatively it may bepresent in an enantiomeric excess of either the L-enantiomer or theD-enantiomer. The acetyl-leucine may be in a single enantiomeric form ofeither the L-enantiomer or the D-enantiomer. In one embodiment, thesingle enantiomeric form is the L-enantiomer. The racemic andenantiomeric forms may be obtained in accordance with known proceduresin the art.

A “pharmaceutically acceptable salt” as referred to herein, is any saltpreparation that is appropriate for use in a pharmaceutical application.Pharmaceutically acceptable salts include, but are not limited to, aminesalts, such as N,N′-dibenzylethylenediamine, chloroprocaine, choline,ammonia, diethanolamine and other hydroxyalkylamines, ethylenediamine,N-methylglucamine, procaine, N-benzylphenethylamine,1-para-chloro-benzyl-2-pyrrolidin-1′-ylmethylbenzimidazole, diethylamineand other alkylamines, piperazine, tris(hydroxymethyl)aminomethane andthe like; alkali metal salts, such as lithium, potassium, sodium and thelike; alkali earth metal salts, such as barium, calcium, magnesium andthe like; transition metal salts, such as zinc, aluminum and the like;other metal salts, such as sodium hydrogen phosphate, disodium phosphateand the like; mineral acids, such as hydrochlorides, sulfates and thelike; and salts of organic acids, such as acetates, lactates, malates,tartrates, citrates, ascorbates, succinates, butyrates, valerates,fumarates and the like.

The acetyl-leucine, or a pharmaceutically acceptable salt of the same,may be formulated and administered to a subject in accordance with knownteachings in the art. For example, the acetyl-leucine, or apharmaceutically acceptable salt of the same, may be formulated as apharmaceutical composition. The pharmaceutical composition may compriseacetyl-leucine, or a pharmaceutically acceptable salt of the same, and apharmaceutically acceptable carrier. Reference to the pharmaceuticalcomposition encompasses the active agent alone or in the form of apharmaceutical composition.

The pharmaceutical composition may take any of a number of differentforms depending, in particular, on the manner in which it is to be used.Thus, for example, it may be in the form of a powder, tablet, capsule,liquid, ointment, cream, gel, hydrogel, aerosol, spray, micellarsolution, transdermal patch, liposome suspension or any other suitableform that may be administered to a person or animal in need oftreatment.

A “pharmaceutically acceptable carrier” as referred to herein, is anyknown compound or combination of known compounds that are known to thoseskilled in the art to be useful in formulating pharmaceuticalcompositions. It will be appreciated that the carrier of thepharmaceutical composition should be one which is tolerated by thesubject to whom it is given.

In one embodiment, the pharmaceutically acceptable carrier may be asolid, and the composition may be in the form of a powder or tablet. Asolid pharmaceutically acceptable carrier may include, but is notlimited to, one or more substances which may also act as flavouringagents, buffers, lubricants, stabilisers, solubilisers, suspendingagents, wetting agents, emulsifiers, dyes, fillers, glidants,compression aids, inert binders, sweeteners, preservatives, dyes,coatings, or tablet-disintegrating agents. The carrier may also be anencapsulating material. In powders, the carrier may be a finely dividedsolid that is in admixture with the finely divided active agentsaccording to the invention. In tablets, the active agent may be mixedwith a carrier having the necessary compression properties in suitableproportions and compacted in the shape and size desired. The powders andtablets may, for example, contain up to 99% of the active agents.Suitable solid carriers include, for example, calcium phosphate,magnesium stearate, talc, sugars, lactose, dextrin, starch, gelatin,cellulose, polyvinylpyrrolidine, low melting waxes and ion exchangeresins. In another embodiment, the pharmaceutically acceptable carriermay be a gel and the composition may be in the form of a cream or thelike.

The carrier may include, but is not limited to, one or more excipientsor diluents. Examples of such excipients are gelatin, gum arabicum,lactose, microcrystalline cellulose, starch, sodium starch glycolate,calcium hydrogen phosphate, magnesium stearate, talcum, colloidalsilicon dioxide, and the like.

In another embodiment, the pharmaceutically acceptable carrier may be aliquid. In one embodiment, the pharmaceutical composition is in the formof a solution. Liquid carriers are used in preparing solutions,suspensions, emulsions, syrups, elixirs and pressurized compositions.The acetyl-leucine may be dissolved or suspended in a pharmaceuticallyacceptable liquid carrier such as water, an organic solvent, a mixtureof both or pharmaceutically acceptable oils or fats. The liquid carriermay contain other suitable pharmaceutical additives such assolubilisers, emulsifiers, buffers, preservatives, sweeteners,flavouring agents, suspending agents, thickening agents, colours,viscosity regulators, stabilizers or osmo-regulators. Suitable examplesof liquid carriers for oral and parenteral administration include water(partially containing additives as above, e.g. cellulose derivatives,such as sodium carboxymethyl cellulose solution), alcohols (includingmonohydric alcohols and polyhydric alcohols, e.g. glycols) and theirderivatives, and oils (e.g. fractionated coconut oil and arachis oil).For parenteral administration, the carrier may also be an oily estersuch as ethyl oleate and isopropyl myristate. Sterile liquid carriersare useful in sterile liquid form compositions for parenteraladministration. The liquid carrier for pressurised compositions may be ahalogenated hydrocarbon or other pharmaceutically acceptable propellant.

Liquid pharmaceutical compositions, which are sterile solutions orsuspensions, may be utilised by, for example, intramuscular,intrathecal, epidural, intraperitoneal, intravenous and particularlysubcutaneous injection. The active agent may be prepared as a sterilesolid composition that may be dissolved or suspended at the time ofadministration using sterile water, saline, or other appropriate sterileinjectable medium.

The compositions may be administered orally in the form of a sterilesolution or suspension containing other solutes or suspending agents(for example, enough saline or glucose to make the solution isotonic),bile salts, acacia, gelatin, sorbitan monoleate, polysorbate 80 (oleateesters of sorbitol and its anhydrides copolymerized with ethylene oxide)and the like. The compositions may also be administered orally either inliquid or solid composition form. Compositions suitable for oraladministration include solid forms, such as pills, capsules, granules,tablets, and powders, and liquid forms, such as solutions, syrups,elixirs, and suspensions. Forms useful for parenteral administrationinclude sterile solutions, emulsions, and suspensions.

Acetyl-leucine and compositions comprising the same may alternatively beadministered by inhalation (e.g. intranasally). Compositions may also beformulated for topical use. For instance, creams or ointments may beapplied to the skin.

Acetyl-leucine may be incorporated within a slow- or delayed-releasedevice. Such devices may, for example, be inserted on or under the skin,and the medicament may be released over weeks or even months. Suchdevices may be advantageous when long-term treatment with acetyl-leucineused according to the present disclosure is required and which wouldnormally require frequent administration (e.g. at least dailyadministration).

In one embodiment, the pharmaceutical composition is in the form of atablet. In tablets, the active agent may be mixed with a vehicle, suchas a pharmaceutically acceptable carrier, having the necessarycompression properties in suitable proportions and compacted in theshape and size desired. The tablets may contain up to 99% by weight ofthe active agents.

For example, the acetyl-leucine, or a pharmaceutically acceptable saltof the same, may be provided in a solid dosage form suitable for oraladministration, notably in the form of a tablet.

Pharmaceutical compositions in solid oral dosage form, such as tablets,may be prepared by any method known in the art of pharmacy.Pharmaceutical compositions are usually prepared by mixing theacetyl-leucine, or a pharmaceutically acceptable salt thereof, withconventional pharmaceutically acceptable carriers.

A tablet may be formulated as is known in the art. Tanganil®, forexample, includes wheat starch, pregelatinised maize (corn) starch,calcium carbonate and magnesium stearate as excipients. The same, orsimilar, excipients, for example, may be employed with the presentdisclosure.

The composition of each 700 mg Tanganil® tablet is as follows: 500 mgacetyl-DL-leucine, 88 mg wheat starch, 88 mg pregelatinised maize (corn)starch, 13 mg calcium carbonate and 11 mg magnesium stearate. The sametablets, for example, may be employed with the present disclosure.

The present disclosure describes acetyl-leucine, including compositionsand methods thereof, for treating a neurodegenerative disease or one ormore symptoms of a neurodegenerative disease in a subject in needthereof. The subject in need thereof may have a genetic, biochemical, orother similar identifiable marker of a neurodegenerative disease. Forexample, the marker of a neurodegenerative disease may be a cellularmarker. The subject in need thereof may have been diagnosed as having aneurodegenerative disease. For example, the subject may have beendiagnosed with a neurodegenerative disease according to a genetic,biochemical, or other similar identifiable marker. The subject in needthereof may be suspected of having or at risk of having aneurodegenerative disease. For example, the subject may have a geneticpredisposition to a neurodegenerative disease (e.g., the subject mayhave one or more family members with a neurodegenerative disease). Thesubject in need thereof may be symptomatic (i.e., have one or moresymptoms associated with a neurodegenerative disease). The subject inneed thereof may be asymptomatic. It should be understood that the terms“symptomatic” and “asymptomatic” are used with reference to symptoms ofa neurodegenerative disease. Subjects who have a genetic, biochemical,or other similar identifiable marker of a neurodegenerative disease,such as subjects who have been diagnosed with a neurodegenerativedisease based on a genetic, biochemical, or other similar identifiablemarker, but who have no further symptoms of the disease are includedwithin the scope of “asymptomatic” for purposes of the presentdisclosure.

As used herein, “treating a neurodegenerative disease or one or moresymptoms of a neurodegenerative disease” and the like refer to delayingonset of a neurodegenerative disease or one or more symptoms of aneurodegenerative disease that would otherwise be expected to manifestaccording to typical disease progression, reducing the severity of aneurodegenerative disease or reducing the severity of or eliminating oneor more existing symptoms associated with a neurodegenerative disease,delaying progression of a neurodegenerative disease or one or moresymptoms of a neurodegenerative disease over time as compared to typicaldisease progression, and/or reversing progression of a neurodegenerativedisease or one or more symptoms of a neurodegenerative disease overtime. “Treating a neurodegenerative disease or one or more symptoms of aneurodegenerative disease” may also refer to improving a biochemicalmarker of a neurodegenerative disease.

As used herein, “typical disease progression,” “disease progression thatwould typically be expected” and the like refer to the typical orexpected progression of a neurodegenerative disease, one or moresymptoms associated with a neurodegenerative disease, or a biochemicalmarker of a neurodegenerative disease if the subject were untreated.Typical or expected disease progression may be based, for example, on aknown scale, index, rating, or score, or other suitable test, forassessing the progression of a neurodegenerative disease, one or moresymptoms of a neurodegenerative disease, or a biochemical marker of aneurodegenerative disease, such as those described as examples herein.The scale, index, rating, score, or other suitable test may correspondto the progression of the disease overall or to the progression of oneor more symptoms associated with the disease. For instance, typical orexpected disease progression may be based on the typical or expectedonset or severity of the neurodegenerative disease or a symptom orcollection of symptoms associated with the neurodegenerative disease.The typical or expected disease progression may be determined on asubject-by-subject basis or may be based on what is typically observedfor or experienced by a collection of subjects afflicted with theneurodegenerative disease, such as a population or subpopulation ofsubjects. Subpopulations may include, for example, subpopulations of thesame gender, of the same or similar age, of the same or similar timingfor the onset of one or more symptoms, etc.

In one embodiment, “treating a neurodegenerative disease or one or moresymptoms of a neurodegenerative disease” refers to delaying onset of aneurodegenerative disease or one or more symptoms of a neurodegenerativedisease that would otherwise be expected to manifest according totypical disease progression. As used herein, “delaying onset of aneurodegenerative disease or one or more symptoms of a neurodegenerativedisease” and the like refer to increasing the time to, or preventing,onset of the neurodegenerative disease or one or more symptoms of theneurodegenerative disease. For example, onset can be said to be delayedwhen the time to manifestation of a neurodegenerative disease or one ormore symptoms of a neurodegenerative disease takes at least 5% longerthan that observed according to typical disease progression. Further,for example, an increase in time of at least 10%, at least 15%, at least20%, at least 25%, at least 30%, at least 40%, at least 50%, at least60%, at least 70%, at least 80%, at least 90% or at least 100% isobserved. In one embodiment, the subject is asymptomatic. Theadministration of acetyl-leucine may be initiated at the time thesubject is asymptomatic to delay onset of a neurodegenerative disease orone or more symptoms of a neurodegenerative disease that would otherwisebe expected to manifest according to typical disease progression. Inanother embodiment, the subject is symptomatic. The administration ofacetyl-leucine may be initiated at the time the subject has somesymptoms in order to delay onset of one or more additional symptoms of aneurodegenerative disease that would otherwise be expected to manifestaccording to typical disease progression. The subject in need thereofmay continue to receive treatment with acetyl-leucine in accordance withthe durations described herein. In one embodiment, the treatmentprevents onset of one or more symptoms of the neurodegenerative diseasethat would otherwise be expected to manifest according to typicaldisease progression.

In one embodiment, “treating a neurodegenerative disease or one or moresymptoms of a neurodegenerative disease” refers to reducing the severityof a neurodegenerative disease or reducing the severity of oreliminating one or more existing symptoms associated with aneurodegenerative disease. The severity of a neurodegenerative diseaseor of the existing symptom(s) may be assessed using a known scale,index, rating, or score, such as those described as examples herein, oranother suitable test for assessing severity. For example, the scale,index, rating, score, or other suitable test may correspond to theseverity of the disease overall or to the severity of one or moresymptoms associated with the disease. In one embodiment, the treatmentimproves such an assessment from a value or degree characteristic of asymptomatic patient to a value or degree characteristic of anon-symptomatic patient.

In one embodiment, “treating a neurodegenerative disease or one or moresymptoms of a neurodegenerative disease” refers to delaying progressionof a neurodegenerative disease or one or more symptoms associated with aneurodegenerative disease over time as compared to typical diseaseprogression, or reversing progression of a neurodegenerative disease orone or more symptoms associated with a neurodegenerative disease overtime. The time over which the treatment delays or reverses progressionmay coincide with the duration of treatment as described herein. Thetreatment may delay or reverse progression over a duration of, forexample, about seven days or more, about two weeks or more, about threeweeks or more, about one month or more, about six weeks or more, aboutseven weeks or more or about two months or more. The treatment may delayor reverse progression over a duration of, for example, about threemonths or more, about four months or more, about five months or more orabout six months or more. It may delay or reverse progression over aduration of, for example, about 1 year or more, about 2 years or more,about 3 years or more, about 4 years or more, about 5 years or more, orabout 10 years or more. The treatment may delay or reverse progressionof the neurodegenerative disease or one or more symptoms associated withthe neurodegenerative disease over the lifetime of the patient.

In one embodiment, “treating a neurodegenerative disease or one or moresymptoms of a neurodegenerative disease” refers to delaying progressionof a neurodegenerative disease or one or more symptoms of aneurodegenerative disease over time as compared to typical diseaseprogression. As used herein, “delaying progression of aneurodegenerative disease or one or more symptoms associated with aneurodegenerative disease over time” and the like refer to slowingand/or stopping progression of the disease or one or more symptoms ofthe disease (e.g., slowing and/or stopping the worsening or increasingseverity of the disease or one or more symptoms of the disease) overtime. Disease progression may be determined, for example, using a knownscale, index, rating, or score, such as those described as examplesherein, or another suitable test for assessing progression. For example,the scale, index, rating, score, or other suitable test may correspondto the progression of the disease overall or to the progression of oneor more symptoms associated with the disease. In one embodiment,“delaying progression of a neurodegenerative disease or one or moresymptoms associated with a neurodegenerative disease” means that asubject's disease severity value (e.g., overall severity or severity ofone or more symptoms) determined by a known scale, index, rating, score,etc., or other suitable test for evaluating severity, does notmeaningfully increase (e.g., at least remains substantially constant).In one embodiment, “delaying progression of a neurodegenerative diseaseor one or more symptoms of a neurodegenerative disease” means preventingthe subject from reaching, or increasing the time taken for a subject toreach (e.g., decreasing the rate of change of increasing severity), aseverity value according to a known scale, index, rating, score, etc.,or other suitable test, for assessing progression compared to a valuecorresponding to typical disease progression. For example, progressioncan be said to be delayed when the time to reach a severity value takesat least 5% longer than that observed according to typical diseaseprogression. Further for example, an increase in time of at least 10%,at least 15%, at least 20%, at least 25%, at least 30%, at least 40%, atleast 50%, at least 60%, at least 70%, at least 80%, at least 90% or atleast 100% is observed. The time over which the treatment delaysprogression of a neurodegenerative disease or one or more symptoms of aneurodegenerative disease may coincide with the duration of treatment asdescribed herein. In one embodiment, the treatment delays progressionfor at least about three months, at least about four months, at leastabout five months, or at least about six months. The treatment may delayprogression for at least about 1 year, at least about 2 years, at leastabout 3 years, at least about 4 years, at least about 5 years, or atleast about 10 years. The treatment may delay progression over thelifetime of the patient.

In one embodiment, “treating a neurodegenerative disease or one or moresymptoms of a neurodegenerative disease” refers to reversing progressionof a neurodegenerative disease or one or more symptoms of aneurodegenerative disease over time. As used herein, “reversingprogression of a neurodegenerative disease or one or more symptoms of aneurodegenerative disease over time” and the like refer to stoppingprogression and reducing the severity of the disease or one or moresymptoms of the disease over time. Disease progression and severity maybe determined, for example, using a known scale, index, rating, orscore, such as those described as examples herein, or another suitabletest for assessing progression and severity. For example, the scale,index, rating, score, or other suitable test may correspond to theprogression and severity of the disease overall or to the progressionand severity of one or more symptoms associated with the disease. In oneembodiment, “reversing progression of a neurodegenerative disease or oneor more symptoms of a neurodegenerative disease over time” means that asubject's disease severity value (e.g., overall severity or severity ofone or more symptoms) determined by a known scale, index, rating, score,etc., or another suitable test, for evaluating severity, improves overtime (i.e., shows a reduction in severity over time). The time overwhich the treatment reverses progression of a neurodegenerative diseaseor one or more symptoms of a neurodegenerative disease may coincide withthe duration of treatment as described herein. In one embodiment, thetreatment reverses progression for at least about three months, at leastabout four months, at least about five months, or at least about sixmonths. In a further embodiment, the treatment reverses progression forat least about 1 year, at least about 2 years, at least about 3 years,at least about 4 years, at least about 5 years, or at least about 10years. The treatment may reverse progression over the lifetime of thepatient.

In one embodiment, “treating a neurodegenerative disease or one or moresymptoms of a neurodegenerative disease” refers to improving in thesubject a biochemical marker of a neurodegenerative disease (e.g.,increased levels of the storage metabolite(s) or secondary biochemicalchanges resulting from the primary storage). A biochemical marker is asignal of disease activity and may provide ongoing indications ofdisease severity and progression over time. In one embodiment, thebiochemical marker is improved in view of a control value. In oneembodiment, the biochemical marker is chosen from increased lysosomalvolume, increased glycosphingolipid (GSL) levels, increasedmicrotubule-associated protein 1A/1B-light chain3-phosphatidylethanolamine conjugate (LC3-II) levels, and increasedamyloid precursor protein C-terminal fragment (APP-CTF) levels. In oneembodiment, the biochemical marker is increased lysosomal volume and thetreatment reduces lysosomal volume in the subject. In one embodiment,the biochemical marker is increased glycosphingolipid (GSL) levels andthe treatment reduces GSL levels in the subject. In one embodiment, thebiochemical marker is increased microtubule-associated protein1A/1B-light chain 3-phosphatidylethanolamine conjugate (LC3-II) levelsand the treatment reduces LC3-II levels in the subject. In oneembodiment, the biochemical marker is increased amyloid precursorprotein C-terminal fragment (APP-CTF) levels and the treatment reducesAPP-CTF levels in the subject. In one embodiment, the treatment improvesa biochemical marker over time. For example, in one embodiment,improving a biochemical marker over time means that the treatmentimproves a biochemical marker over time toward a control value, preventsthe progression of a biochemical marker over time, and/or delays theprogression of the biochemical marker over time as compared to typicaldisease progression. The time over which the treatment improves abiochemical marker may coincide with the duration of treatment asdescribed herein. In one embodiment, the treatment improves abiochemical marker for at least about three months, at least about fourmonths, at least about five months, or at least about six months. Thetreatment may improve a biochemical marker for at least about 1 year, atleast about 2 years, at least about 3 years, at least about 4 years, atleast about 5 years, or at least about 10 years. The treatment mayimprove the biochemical marker over the lifetime of the patient.

A “symptom” of a neurodegenerative disease includes any clinical orlaboratory manifestation associated with a neurodegenerative disease andis not limited to what the subject can feel or observe. Symptoms asdescribed herein include, but are not limited to, neurological symptomsand psychiatric symptoms. Examples of neurological symptoms includeataxia, other movement disorders such as hypokinesia, rigor, tremor ordystonia, central ocular motor disorders such as vertical and horizontalsupranuclear saccade/gaze palsy and neuropsychological deficits such asdementia.

Examples of psychiatric symptoms include depression, behaviouraldisoders or psychosis. Onset of symptoms may range from birth toadulthood.

Progression of a neurodegenerative disease over time or throughtreatment can be monitored, for example, using one or more known testsat two or more time points and comparing the results. Diseaseprogression and/or severity can be assessed, for example, using theScale for the Assessment and Rating of Ataxia (SARA), SpinocerebellarAtaxia Functional Index (SCAFI), the International Cooperative AtaxiaRating Scale (ICARS), the brief ataxia rating scale (BARS), the modifiedDisability Rating Scale (mDRS), EuroQol 5Q-5D-5L (EQ-5D-5L), the visualanalogue scale (VAS), neuropsychological tests, such as Wechsler AdultIntelligence Scale-Revised (WAIS-R), Wechsler Intelligence Scale forChildren-IV (WISC-IV), Montreal Cognitive Assessment (MoCA), as well asscales used in movement disorders, such as the Unified Parkinson'sRating Scale (UPRS) or the Unified Multiple System Atrophy Rating Scale(UMSARS), or other suitable tests. For certain LSDs, such as NPC,particular scores have been developed and validated over the lastdecades, for instance the clinical severity score (CSS) and annualseverity increment score (ASIS) (see Yanjanin et al., “Linear ClinicalProgression, Independent of Age of Onset, in Niemann-Pick Disease, TypeC,” Am J Med Genet Part B 153B:132-14o) and the modified 6-Domain NP-Cdisability Scale (mDRS score). For example, an NPC patient's severitycan be quantified by assigning a CSS, which assesses various parametersof the disease (ambulation, seizures, eye movement, etc.) and gives eachparameter a score out of 5. A higher score equals a greater severity.The ASIS quantifies the annual rate of change in the CSS, calculated bydividing the CSS by the patient's age. In this regard, certain scores inthese tests are characteristic of symptomatic neurodegenerative diseasepatients and evidence disease progression and/or severity.

Thus, “treating a neurodegenerative disease or one or more symptoms of aneurodegenerative disease”, for example, may be equated to achieving animproved assessment, such as those described herein, of a SARA, SCAFI,ICARS, BARS, mDRS, EQ-5D-5L, VAS, WAIS-R, WISC-IV, CSS, UPRS, UMSARS,and/or MoCA score, or result of another test suitable for characterisinga neurodegenerative disease patient. For example, in one embodiment,“reducing the severity of a neurodegenerative disease or reducing theseverity of or eliminating one or more existing symptoms of aneurodegenerative disease” means improving a SARA, SCAFI, ICARS, BARS,mDRS, EQ-5D-5L, VAS, WAIS-R, WISC-IV, CSS, UPRS,UMSARS, and/or MoCAscore, or a result of another suitable test, for evaluating severity,such as improving the score or result from a severity valuecharacteristic of a symptomatic subject to a value characteristic of anon-symptomatic subject. In another embodiment, “delaying progression ofa neurodegenerative disease or one or more symptoms of aneurodegenerative disease” means that a subject's SARA, SCAFI, ICARS,BARS, mDRS, EQ-5D-5L, VAS, WAIS-R, WISC-W, CSS, UPRS, UMSARS, and/orMoCA score, or a result of another suitable test for evaluatingprogression, does not meaningfully increase (e.g., at least remainssubstantially constant). In a further embodiment, “delaying progressionof a neurodegenerative disease or one or more symptoms associated with aneurodegenerative disease” means preventing a subject's SARA, SCAFI,ICARS, BARS, mDRS, EQ-5D-5L, VAS, WAIS-R, WISC-W, CSS, UPRS, UMSARS,and/or MoCA score, or a result of another suitable test for evaluatingprogression, from reaching, or increasing the time taken to reach, avalue compared to that of typical disease progression. In anotherembodiment, “reversing progression of a neurodegenerative disease or oneor more symptoms of a neurodegenerative disease over time” means that asubject's SARA, SCAFI, mDRS, EQ-5D-5L, VAS, WAIS-R, WISC-W, CSS and/orMoCA score, or a result of another suitable test for evaluatingprogression, improves over time (i.e., shows a reduction in severityover time).

For example, to evaluate overall neurological status, mDRS, afour-domain scale (ambulation, manipulation, language and swallowing),may be applied. Cerebellar function may be evaluated using SARA, aneight-item clinical rating scale (gait, stance, sitting, speech, finemotor function and taxis; range 0-40, where 0 is the best neurologicalstatus and 40 the worst), and SCAFI, comprising the 8-m-Walking-Time(8MW; performed by having patients walking twice as quickly as possiblefrom one line to another excluding turning), 9-Hole-Peg-Test (9HPT) andthe number of “PATA” repetitions over 10 s. Subjective impairment andquality of life may be evaluated using the EQ-5D-5L questionnaire andVAS. To assess ocular motor function, 3-dimensional videooculography(EyeSeeCam) may be used to measure the peak velocity of saccades, gainof smooth pursuit, peak slow phase velocity of gaze-evoked nystagmus(gaze-holding function), peak slow phase velocity of optokineticnystagmus, and gain of horizontal vestibulo-ocular reflex. To evaluatethe cognitive state, WAIS-R or WISC-W, and MoCA, assessing differentcognitive domains, including attention and concentration, executivefunctions, memory, language, visuoconstructional skills, conceptualthinking, calculations, and orientation with a maximum of 30 points anda cut-off score of 26, may be used. The skilled person will know how toperform these and other such tests.

The acetyl-leucine, or a pharmaceutically acceptable salt of the same,may be administered, for example, at a dose ranging from about 500 mg toabout 15 g per day or ranging from about 500 mg to about 10 g per day,such as ranging from about 1.5 g to about 10 g per day, optionally bysolid oral or liquid oral route. The acetyl-leucine, or apharmaceutically acceptable salt of the same, may be administered, forexample, in a dose according to that of Tanganil®, which is prescribedto adults in a dose of 1.5 g to 2 g per day, 3-4 tablets in two doses,morning and evening.

If one enantiomer is administered, the doses may be reduced accordingly.For instance if only acetyl-L-leucine or if only acetyl-D-leucine isadministered, the dose may range from about 250 mg to about 15 g perday, range from about 250 mg to about 10 g per day, or range from about250 mg to about 5 g per day, such as from about 0.75 g to about 5 g perday.

In one embodiment, the administered dose ranges from about 1 g to about15 g per day, from about 1 g to about 10 g per day, or from about 1.5 gto about 7 g per day. It may be from about 2, 3, 4, 5, 6, 7, 8, 9, 10,11, 12, 13, or 14 g to about 15 g per day. It may be from about 2, 3, 4,5, 6, 7, 8 or 9 g to about 10 g per day. It may be more than about 1.5 gper day, but less than about 15, 14, 13, 12, 11, 10, 9, 8, 7, 6 or 5 gper day. In one embodiment, the dose ranges from about 4 g to about 6 gper day. In one embodiment, the dose ranges from about 4 g to about 5 gper day. In one embodiment, the dose is about 4.5 g per day. In oneembodiment, the dose is about 5 g per day. In one embodiment, thesedoses are administered in a solid oral dosage form, notably tablets. Inanother embodiment, these doses are for acetyl-leucine when in itsracemic form. Doses for acetyl-leucine when an enantiomeric excess ispresent may be lower than those recited here, for example, around 50%lower. The above recited dose-ranges when halved are thus alsoexplicitly encompassed by the present disclosure.

The total daily dose may be spread across multiple administrations, i.e.administration may occur two or more times a day to achieve the totaldaily dose. As an example, the required number of tablets to provide thetotal daily dose of acetyl-leucine may be split across twoadministrations (for example, in the morning and evening) or threeadministrations (for example, in the morning, noon and evening). Eachdose may be suitably administered with or without food. For example,acetyl-leucine may be dosed by about 1 or about 2 hours before meals,such as at least about 20 minutes, at least about 30 minutes, at leastabout 40 minutes, or at least about 1 hour before meals, or may be dosedby about 1, about 2, or about 3 hours after meals, such as waiting atleast about 20 minutes, at least about 30 minutes, at least about 1hour, at least about 1.5 hours, at least about 2 hours, or at leastabout 2.5 hours after meals. For example, a total daily dose of 4.5 gacetyl-DL-leucine may be administered as three Tanganil® (or equivalent)tablets before, with, or after breakfast, three further tablets before,with, or after lunch and three further tablets before, with, or afterdinner.

Administration of acetyl-leucine in accordance with the presentdisclosure may be initiated before or after a subject is found to have agenetic, biochemical, or other similar identifiable marker of aneurodegenerative disease, such as, in the case of the former, when thesubject is suspected of having or is at risk of having aneurodegenerative disease. Administration may be initiated at or aroundthe time a subject is found to have a genetic, biochemical, or othersimilar identifiable marker of a neurodegenerative disease. Similarly,administration may be initiated before, at or around the time, or aftera subject is diagnosed with a neurodegenerative disease, such as before,at or around the time, or after a subject is found to have a genetic,biochemical, or other similar identifiable marker of a neurodegenerativedisease. Administration of acetyl-leucine may be initiated when thesubject is symptomatic or asymptomatic. In particular, one of theadvantages of treatment with acetyl-leucine, according to the presentdisclosure, is that the administration of acetyl-leucine may beinitiated as early as the time after a subject is found to have agenetic and/or biochemical marker of a neurodegenerative disease butbefore the subject shows symptoms of the neurodegenerative disease(other than the genetic and/or biochemical marker, i.e., the subject isasymptomatic) or before the subject shows one or more symptomsconsidered hallmarks of the disease. The treatment may delay onset ofthe neurodegenerative disease or one or more symptoms associated withthe neurodegenerative disease, as described herein. The treatment mayalso be continued for a duration as described herein.

As discussed herein, an advantage of treatment with acetyl-leucine,according to the present disclosure, is that acetyl-leucine may beadministered over a long duration of time to, for example, delay or evenreverse progression of a neurodegenerative disease or one or moresymptoms of a neurodegenerative disease in a subject as compared totypical disease progression. Treatment duration may be, for example,about seven days or more, about two weeks or more, about three weeks ormore, about one month or more, about six weeks or more, about sevenweeks or more, or about two months or more. In one embodiment, it isabout three months or more, about four months or more, about five monthsor more or about six months or more. The treatment duration may be about1 year or more, about 2 years or more, about 4 years or more, about 5years or more, or about 10 years or more. The treatment duration may bethe life-time of the patient.

Any and all combinations of dosage form, dose amount, dosing scheduleand treatment duration are envisaged and encompassed by the invention.In one embodiment, the dose is from about 4 g to about 10 g per day,taken across one, two, or three administrations per day, for a treatmentduration of about two months or more. In another embodiment, the dose ismore than 4 g but no more than 5 g per day, taken across one, two, orthree administrations per day, for a treatment duration of about sixmonths or more. The dosage form may be a solid oral dosage form, notablytablets.

The pharmaceutical composition may be used as a monotherapy (e.g., useof the active agent alone) for treating a neurodegenerative disease in asubject. Alternatively, the pharmaceutical composition may be used as anadjunct to, or in combination with, other known therapies, e.g., fortreating a neurodegenerative disease in a subject.

The neurodegenerative disease may, but need not, be associated withlysosomal dysfunction (e.g., lysosomal storage defect).Neurodegenerative diseases, according to the present disclosure, notassociated with lysosomal dysfunction include, but are not limited to,Alexander's disease, Alper's disease, cerebral palsy, Cockayne syndrome,corticobasal degeneration, HIV-associated dementia, Kennedy's disease,neuroborreliosis, primary lateral sclerosis, Refsum's disease,Schilder's disease, subacute combined degeneration of spinal cordsecondary to pernicious anaemia, hereditary motor and sensory neuropathywith proximal dominance, Wobbly Hedgehog Syndrome (WHS), progressivemuscular atrophy (Duchenne-Aran muscular atrophy), progressive bulbarpalsy, pseudobulbar palsy, HIV-associated neurocognitive disorders(HAND), Vascular Parkinsonism, lower body Parkinson's syndrome,cerebellar downbeat nystagmus, and cerebellar ataxia, which includesSpinocerebellar ataxia (SCA) 4, Spinocerebellar ataxia (SCA) 5(Lincoln's Ataxia), Spinocerebellar ataxia (SCA) 8, SpinocerebellarAtaxia (SCA) 10, Spinocerebellar Ataxia (SCA) 11, Spinocerebellar Ataxia(SCA) 12, Spinocerebellar Ataxia (SCA) 13, Spinocerebellar Ataxia (SCA)14, Spinocerebellar Ataxia (SCA) 15/16, Spinocerebellar Ataxia (SCA) 18(sensory/motor neuropathy with ataxia), Spinocerebellar Ataxia (SCA)19/22, Spinocerebellar Ataxia (SCA) 20, Spinocerebellar Ataxia (SCA) 21,Spinocerebellar Ataxia (SCA) 23, Spinocerebellar Ataxia (SCA) 25,Spinocerebellar Ataxia (SCA) 26, Spinocerebellar Ataxia (SCA) 27,Spinocerebellar Ataxia (SCA) 29, Spinocerebellar Ataxia (SCA) 30,Spinocerebellar Ataxia (SCA) 31, Spinocerebellar Ataxia (SCA) 32,Spinocerebellar Ataxia (SCA) 35, Spinocerebellar Ataxia (SCA) 36,Episodic Ataxia (EA) 1, Episodic Ataxia (EA) 2, Episodic Ataxia (EA) 3,Episodic Ataxia (EA) 4, Episodic Ataxia (EA) 5, Episodic Ataxia (EA) 6,Episodic Ataxia (EA) 7, Spinocerebellar Ataxia (SCA) 28, SpinocerebellarAtaxia (SCA) 24 (spinocerebellar ataxia autosomal recessive type 4(SCAR4); Spinocerebellar ataxia with saccadic intrusions), Tabesdorsalis, Ataxia with Oculomotor Apraxia Type 1 (AOA1), Ataxia withOculomotor Apraxia Type 2 (AOA2), Ataxia with Oculomotor Apraxia Type 4(AOA4), spinocerebellar ataxia autosomal recessive type 10 (SCAR 10),mitochondrial recessive ataxia syndrome (MIRAS), Myclonic EpilepsyMyopathy Sensory Ataxia (MEMSA), Sensory Ataxic Neuropathy DysarthriaOpthalmoparesis (SANDO), infantile-onset spinocerebellar ataxia,Hereditary Spastic Paraplegia 7 (HSP SPG7 gene), mitochondrial myopathy,encephalopathy, lactacidosis, stroke syndrome (MELAS), myoclonicepilepsy with ragged red fibers (MERRF), neurogenic muscle weakness,ataxia, and retinitis pigmentosa (NARP), Kearns-Sayre (KSS), Fragile Xtremor/ataxia syndrome (FXTAS), Arts Syndrome, X-linked SpinocerebellarAtaxia 1, X-linked Spinocerebellar Ataxia 2, X-linked SpinocerebellarAtaxia 3, X-linked Spinocerebellar Ataxia 4 or X-linked SpinocerebellarAtaxia 5, Christianson type X-linked syndromic mental retardation,X-linked sideroblastic anemia, Idiopathic Late-Onset Cerebellar Ataxia,Sporadic Adult-Onset Ataxia of Unknown Etiology (SAOA), and cerebellarataxia, neuropathy, vestibular areflexia syndrome (CANVAS). In oneembodiment, the neurodegenerative disease not associated with lysosomaldysfunction is corticobasal degeneration, SCA 28, and AOA4.

As mentioned above, many neurodegenerative diseases are associated withlysosomal dysfunction, which includes both neurodegenerative lysosomalstorage disorders (LSDs) and many other neurodegenerative diseases wherelinks to lysosomal defects have been suggested. See, e.g., Boman et al.,Journal of Parkinson's Disease, vol. 6, no. 2, pp. 307-315 (May 2016);Makioka et al., Neuroreport, 23(5):270-276 (March 2012); Orr et al.,Alzheimer's Research & Therapy, 5:53 (Oct. 2013); Barlow et al., Proc.Nat'l. Acad. Sci. USA, 18;97(2):871-6 (2000).

In one embodiment, the neurodegenerative disease is associated withlysosomal dysfunction (e.g., lysosomal storage defect).Neurodegenerative diseases, according to the present disclosure,associated with lysosomal dysfunction include, but are not limited to,alcoholism, Alzheimer's disease, amyotrophic lateral sclerosis (ALS),Canavan disease, frontotemporal lobar degeneration, Huntington'sdisease, Lewy body dementia, multiple system atrophy (MSA-P/MSA-C),multiple sclerosis, narcolepsy, Parkinson's Disease, Smith Lemli OpitzSyndrome (SLOS) (an inborn error of cholesterol synthesis), Tangierdisease, Pelizaeus-Merzbacher Disease, Pick's disease, frontotemporaldementia and parkinsonism linked to chromosome 17, prion diseases,including scrapie, transmissible mink encephalopathy, chronic wastingdisease, bovine spongiform encephalopathy (BSE), feline spongiformencephalopathy, exotic ungulate encephalopathy, kuru, Creutzfeldt-Jakobdisease, Gerstmann-Sträussler-Scheinker syndrome, and fatal familialinsomnia, progressive supranuclear palsy, spinal muscular atrophy,neurodegenerative LSDs, and cerebellar ataxia, whichincludesSpinocerebellar Ataxia (SCA) 1, Spinocerebellar Ataxia (SCA) 2,Spinocerebellar Ataxia (SCA) 3 (Machado-Joseph disease), SpinocerebellarAtaxia (SCA) 6, Spinocerebellar Ataxia (SCA) 7, Spinocerebellar Ataxia(SCA) 17, dentatorubral-pallidoluysian atrophy, Autosomal RecessiveSpastic Ataxia of Charlevoix-Saguenay (ARSACS), autosomal recessivecerebellar ataxia type 1 (Recessive Ataxia of Beauce (RAB), SYNE-1mutation), autosomal recessive cerebellar ataxia type 2 (spinocerebellarataxia autosomal recessive 9, SCAR9), ataxia with vitamin E deficiency(AVED), ataxia telangiectasia (Louis Barr disease), Freidreich's ataxia(FRDA), and ataxia with coenzyme Q10 deficiency. In one embodiment, theneurodegenerative disease associated with lysosomal dysfunction ischosen from alcoholism, Alzheimer's disease, amyotrophic lateralsclerosis (ALS), Canavan disease, frontotemporal lobar degeneration,Huntington's disease, multiple system atrophy (MSA-P/MSA-C), multiplesclerosis, narcolepsy, Parkinson's Disease, Smith Lemli Opitz Syndrome(SLOS) (an inborn error of cholesterol synthesis), Tangier disease,Pelizaeus-Merzbacher Disease, Pick's disease, frontotemporal dementia,frontotemporal dementia with parkinsonism, prion diseases, progressivesupranuclear palsy, and spinal muscular atrophy. In one embodiment, theneurodegenerative disease associated with lysosomal dysfunction ischosen from ALS, MSA-P, MSA-C, frontotemporal dementia withparkinsonism, progressive supranuclear palsy, SCA 28, SCA 1, andAlzheimer's disease.

Neurodegenerative LSDs are characterized by the accumulation ofundigested or partially digested macromolecules resulting in cellulardysfunction and neurodegeneration, which is often progressive leading tophysical disability and/or mental deterioration. They tend to present inthe first few years of life and the severe progression results infrequent hospitalization. If left untreated, patients often die in theirmid-teens. Adult-onset patients have also been described.Neurodegenerative LSDs, according to the present disclosure, include,but are not limited to, neuronal ceroid lipofuscinoses (Types 1-10),Gaucher disease Type 2/3 (neuronopathic), Krabbe disease, multiplesulfatase deficiency, mucolipidoses, including mucolipidosis I,mucolipidosis II, and mucolipidosis IV, Niemann-Pick Disease Type A,Niemann-Pick Disease Type B, Niemann-Pick Disease Type C,Infantile-Onset Pompe Disease, Late-Onset Pompe Disease, Tay-Sachsdisease, Sandhoff disease, Farber disease, galactosialidosis, Fabrydisease, Schindler disease, GM1 gangliosidosis, AB variant GM2gangliosidosis, metachromatic leukodystrophy (MLD),mucopolysaccharidoses, including MPS IH, MPS IS, MPS IH-S, MPS II, MPSIIIA, MPS IIIB, MPS IIIC, MPS IIID, and MPS VII, beta-mannosidosis,aspartylglucosaminuria, fucosidosis, Salla disease, infantile freesialic acid storage disease (ISSD), and Danon disease. In oneembodiment, the neurodegenerative LSD is chosen from NPC, NPA,mucolipidosis II, MPS IIIB, aspartylglucosaminuria, mucolipidosis IIIA,MPS VII, Sandhoff disease, Tay-Sachs disease, the AB variant ofTay-Sachs disease, and GM1 gangliosidosis. In one embodiment, theneurodegenerative disease is not chosen from a neurodegenerative LSD.

In one embodiment, the neurodegenerative disease is a Motor NeuronDisease. In one embodiment, the Motor Neuron Disease is chosen fromprimary lateral sclerosis, progressive muscular atrophy, progressivebulbar palsy, pseudobulbar palsy, ALS, Alzheimer's disease, Canavandisease, frontotemporal lobar degeneration, Huntington's disease,multiple sclerosis, narcolepsy, Parkinson's Disease,Pelizaeus-Merzbacher disease, and spinal muscular atrophy.

In one embodiment, the neurodegenerative disease is cerebellar ataxia.In one embodiment, the neurodegenerative disease is Niemann-Pickdisease. In one embodiment, the neurodegenerative disease isNiemann-Pick type C. In one embodiment, the neurodegenerative disease isNiemann-Pick type A. In one embodiment, the neurodegenerative disease isparkinsonism. In one embodiment, the neurodegenerative disease isneuronopathic Gaucher disease. In one embodiment, the neurodegenerativedisease is Tay-Sachs disease. In one embodiment, the neurodegenerativedisease is Sandhoff s disease. In one embodiment, the neurodegenerativedisease is Fabry disease. In one embodiment, the neurodegenerativedisease is GM1 gangliosidosis. In one embodiment, the neurodegenerativedisease is Louis-Barr syndrome. In one embodiment, the neurodegenerativedisease is Alzheimer's disease. In one embodiment, the neurodegenerativedisease is Parkinson's disease. In one embodiment, the neurodegenerativedisease is multiple system atrophy. In one embodiment, theneurodegenerative disease is multiple system atrophy type C (MSA-C). Inone embodiment, the neurodegenerative disease is multiple system atrophytype P (MSA-P). In one embodiment, the neurodegenerative disease isfronto-temporal dementia. In one embodiment, the neurodegenerativedisease is fronto-temporal dementia with parkinsonism. In oneembodiment, the neurodegenerative disease is lower body Parkinson'ssyndrome. In one embodiment, the neurodegenerative disease isamyotrophic lateral sclerosis (ALS). In one embodiment, theneurodegenerative disease is corticobasal-degeneration-syndrome. In oneembodiment, the neurodegenerative disease is progressive supranuclearpalsy. In one embodiment, the neurodegenerative disease is cerebellardownbeat nystagmus. In one embodiment, the neurodegenerative disease isSCA 28. In one embodiment, the neurodegenerative disease is ataxiatelangiectasia. In one embodiment, the neurodegenerative disease isSCA 1. In one embodiment, the neurodegenerative disease is AOA4.

Major symptoms of Parkinson's Disease (PD) include rigidity, tremor, andslow movement. There are other diseases in which these symptoms areprevalent. These diseases, and PD itself, fall under the umbrella termParkinsonism. PD can be referred to as Primary Parkinsonism. Otherexamples of Parkinsonisms include: Multiple System Atrophy; ProgressiveSupranuclear Palsy; Normal pressure hydrocephalus; and Vascular orarteriosclerotic parkinsonism. Those diseases that can be classed asParkinsonisms, but are not PD, can also be referred to as“Parkinson-Plus Syndromes”. Unlike PD patients, individuals withParkinson-Plus Syndromes do not respond to L-Dopa. The term“parkinsonism” as used herein may refer to a motor syndrome whose mainsymptoms are tremor at rest, stiffness, slowing of movement and posturalinstability. Parkinsonian syndromes can be divided into four subtypes,according to their origin: primary or idiopathic; secondary or acquired;hereditary parkinsonism; and Parkinson plus syndromes or multiple systemdegeneration.

In one embodiment, the parkinsonism is a Parkinson plus syndrome ormultiple system degeneration.

In one embodiment, the parkinsonism is vascular (arteriosclerotic)Parkinsonism, lower-body Parkinsonism, Multiple System Atrophy withpredominant parkinsonism (MSA-P), Multiple System Atrophy withcerebellar features (MSA-C; Sporadic olivopontocerebellar atrophy(OPCA)), Shy-Drager syndrome, Progressive Supranuclear Palsy(Steele-Richardson-Olszewski syndrome), Lewy body dementia, Pick'sdisease, or frontotemporal dementia and parkinsonism linked tochromosome 17.

Niemann-Pick diseases are a heterogeneous group of autosomal recessiveLSDs. Common cellular features include abnormal sphingomyelin (SM)storage in mononuclear phagocytic cells and parenchymal tissues, as wellas (hepato)splenomegaly. Among the three main subgroups of Niemann-Pickdisease (A-C), NPC (previously classified as NPC and NPD and nowappreciated to be a single disease) is classified as a fatalneurovisceral LSD caused by abnormal intracellular cholesteroltransport-induced accumulation of unesterified cholesterol in lateendosome/lysosomal compartments. Outside the CNS, the cellularcharacteristics of NPC include abnormal accumulation of unesterifiedcholesterol and other lipids (e.g. GSLs) within late endosome/lysosomalcompartments. Conversely, there is no net elevation in cholesterol inthe CNS (although it does have an altered distribution) but there arehighly elevated levels of GSLs. Progressive neurodegeneration isparticularly characterised by sequential degeneration of GABAergicPurkinje neurons in the cerebellum, which parallels the onset andprogression of cerebellar ataxia and other aspects of neurologicaldysfunctions seen during the course of NPC. Genetic studies have shownthat NPC disease is caused by mutations in either the Npc1 or Npc2genes. The precise mechanistic link between these two genes remainsunknown and the functional roles of these proteins remains enigmatic.NPC1 encodes a multimembrane spanning protein of the limiting membraneof the late endosome/lysosome, whereas NPC2 is a soluble cholesterolbinding protein of the lysosome. When NPC1 is inactivated, sphingosineis the first lipid to be stored, suggesting that NPC1 plays a role inthe transport of sphingosine from the lysosome, where it is normallygenerated as part of sphingolipid catabolism. Elevated sphingosine inturn causes a defect in calcium entry into acidic stores resulting ingreatly reduced calcium release from this compartment. This thenprevents late endosome-lysosome fusion, which is a calcium dependentprocess, and causes the secondary accumulation of lipids (cholesterol,sphingomyelin and glycosphingolipids) that are cargos in transit throughthe late endocytic pathway. Other secondary consequences of inhibitingNPC1 function include defective endocytosis and failure to clearautophagic vacuoles. It has been shown that the NPC1/NPC2 cellularpathway is targeted by pathogenic mycobacteria to promote their survivalin late endosomes.

The NPC mouse model shares a number of pathological features with, e.g.,Alzheimer's disease (AD). Microtubule-associated protein 1A/1B-lightchain 3-phosphatidylethanolamine conjugate (LC3-II) levels havepreviously been reported to be elevated in the NPC mouse. LC3-II is amarker of autophagosome formation, and increased levels of LC3-II canreflect impaired clearance of autophagic vacuoles. Autophagosomes areformed, but are not cleared. Autophagy is impaired in AD, and AD brainsexhibit increased levels of LC3-II. In addition, amyloid precursorprotein (APP) is the precursor molecule whose proteolysis generates betaamyloid (Aβ). Aβ plaques are a hallmark of the AD brain and have beenproposed to be a causative factor in disease pathology. Amyloidprecursor protein C-terminal fragments (APP-CTFs), which are anintermediate in the proteolysis of APP to Aβ, accumulate in the AD brainand also progressively accumulate in the brains of NPC1 mice.

Tay-Sachs disease is a fatal hereditary disorder of lipid metabolismcharacterised especially in CNS tissue due to deficiency of the Aisozyme of β-hexosaminidase. Mutations in the HEXA gene, which encodesthe α subunit of β-hexosaminidase, cause the A isozyme deficiency.Tay-Sachs is a prototype of a group of disorders, the GM2gangliosidoses, characterized by defective GM2 ganglioside degradation.The GM2 ganglioside (monosialylated ganglioside 2) accumulates in theneurons beginning already in fetal life.

Sandhoff disease results from a deficiency of both the A and B (basic)isozymes of β-hexosaminidase. Mutations in the HEXB gene, which encodesthe β subunit of β-hexosaminidase, cause the B isozyme deficiency.

GM1 gangliosidosis is caused by a deficiency of β-galactosidase, whichresults in lysosomal storage of GM1 ganglioside (monosialylatedganglioside 1).

Fabry disease is caused by a deficiency of a-galactosidase, whichresults in lysosomal storage of a ceramide trihexoside.

In one embodiment, the neurodegenerative disease is not cerebellarataxia. In one embodiment, the neurodegenerative disease is not NiemannPick disease. In one embodiment, the neurodegenerative disease is notNiemann Pick type C disease. In one embodiment, the neurodegenerativedisease is not cerebellar ataxia or Niemann Pick disease (e.g., NiemannPick type C disease).

In one embodiment, the acetyl-leucine, or a pharmaceutically acceptablesalt thereof, treats weight loss, gait deterioration, and/or motorfunction deterioration associated with Niemann-Pick disease (e.g.,Niemann-Pick type C or A) or mucolipidosis type II. For example, theacetyl-leucine, or a pharmaeutically acceptable salt thereof, may delayonset of, reduce the severity of or eliminate, or delay or reverse theprogression of weight loss, gait deterioration, and/or motor functiondeterioration associated with Niemann-Pick disease (e.g. Niemann-Picktype C or A) or mucolipidosis type II. In one embodiment, the weightloss, gait deterioration, and/or motor function deterioration isassociated with Niemann-Pick type A or mucolipidosis type II.

In one embodiment, the acetyl-leucine, or a pharmaceutically acceptablesalt thereof, treats gait deterioration, motor function deteriorationand/or reduced mobility associated with Sandhoff s disease. For example,the acetyl-leucine, or a pharmaceutically acceptable salt thereof, maydelay onset of, reduce the severity of or eliminate, or delay or reversethe progression of gait deterioration, motor function deterioration,and/or reduced mobility associated with Sandhoff s disease.

In one embodiment, the acetyl-leucine, or a pharmaceutically acceptablesalt thereof, treats reduced co-ordination, tremors, reduced mobility,cognitive impairment, and/or gait deterioration associated withTay-Sachs disease. For example, the acetyl-leucine, or apharmaceutically acceptable salt thereof, may delay onset of, reduce theseverity of or eliminate, or delay or reverse the progression of reducedco-ordination, tremors, reduced mobility, cognitive impairment, and/orgait deterioration associated with Tay-Sachs disease.

In one embodiment, the acetyl-leucine, or a pharmaceutically acceptablesalt thereof, treats speech deterioration (e.g., fluency of speechand/or modulation of voice), gait deterioration, reduced mobility,reduced swallowing functions, and/or paresis associated with amyotrophiclateral sclerosis (ALS). For example, the acetyl-leucine, or apharmaceutically acceptable salt thereof, may delay onset of, reduce theseverity of or eliminate, or delay or reverse the progression of speechdeterioration (e.g., fluency of speech and/or modulation of voice), gaitdeterioration, reduced mobility, reduced swallowing functions, and/orparesis associated with ALS. In another embodiment, the acetyl-leucine,or a pharmaceutically acceptable salt thereof treats reduced sleepquality associated with ALS. For example, the acetyl-leucine, or apharmaceutically acceptable salt thereof, may delay onset of, reduce theseverity of or eliminate, or delay or reverse the progression of reducedsleep quality associated with ALS.

In one embodiment, the acetyl-leucine, or a pharmaceutically acceptablesalt thereof, treats speech deterioration, gait deterioration, and/orincreased propensity to falls associated with multisystemic atrophycerebellar type (MSA-C). For example, the acetyl-leucine, or apharmaceutically acceptable salt thereof, may delay onset of, reduce theseverity of or eliminate, or delay or reverse the progression of speechdeterioration, gait deterioration, and/or increased propensity to fallsassociated with MSA-C.

In one embodiment, the acetyl-leucine, or a pharmaceutically acceptablesalt thereof, treats gait deterioration, increased propensity to falls,and/or speech deterioration associated with fronto-temporal dementiawith parkinsonism. For example, the acetyl-leucine, or apharmaceutically acceptable salt thereof, may delay onset of, reduce theseverity of or eliminate, or delay or reverse the progression of gaitdeterioration, increased propensity to falls, and/or speechdeterioration associated with fronto-temporal dementia withparkinsonism.

In one embodiment, the acetyl-leucine, or a pharmaceutically acceptablesalt thereof, treats increased propensity to falls and/or gaitdeterioration associated with corticobasal-degeneration-syndrome. Forexample, the acetyl-leucine, or a pharmaceutically acceptable saltthereof, may delay onset of, reduce the severity of or eliminate, ordelay or reverse the progression of increased propensity to falls and/orgait deterioration associated with corticobasal-degeneration-syndrome.

In one embodiment, the acetyl-leucine, or a pharmaceutically acceptablesalt thereof, treats gait deterioration associated with progressivesupranuclear palsy. For example, the acetyl-leucine, or apharmaceutically acceptable salt thereof, may delay onset of, reduce theseverity of or eliminate, or delay or reverse the progression of gaitdeterioration associated with progressive supranuclear palsy.

In one embodiment, the acetyl-leucine, or a pharmaceutically acceptablesalt thereof, treats oscillopsia, deterioration of spatial orientation,deterioration of visual acuity, and/or increase in postural swayassociated with cerebellar downbeat nystagmus. For example, theacetyl-leucine, or a pharmaceutically acceptable salt thereof, may delayonset of, reduce the severity of or eliminate, or delay or reverse theprogression of oscillopsia, deterioration of spatial orientation,deterioration of visual acuity, and/or increase in postural swayassociated with cerebellar downbeat nystagmus.

There is also provided a method of treating a neurodegenerative diseaseor one or more symptoms of a neurodegenerative disease in a subject inneed thereof, the method comprising administering a therapeuticallyeffective amount of acetyl-leucine, or a pharmaceutically acceptablesalt thereof, to the subject.

A “therapeutically effective amount” of an agent is any amount which,when administered to a subject, is the amount of agent that is needed toproduce the desired effect, which, for the present disclosure, can betherapeutic and/or prophylatic. The dose may be determined according tovarious parameters, such as the specific form of acetyl-leucine used;the age, weight and condition of the patient to be treated; the type ofthe disease; the route of administration; and the required regimen. Aphysician will be able to determine the required route of administrationand dosage for any particular patient. For example, a daily dose may befrom about 10 to about 225 mg per kg, from about 10 to about 150 mg perkg, or from about 10 to about 100 mg per kg of body weight.

Also disclosed is a kit for treating a neurodegenerative disease in asubject, comprising a means for diagnosing or prognosing thedisease/disorder, and acetyl-leucine or a pharmaceutically acceptablesalt thereof.

The means for diagnosing or prognosing a neurodegenerative disease mayinclude a specific binding agent, probe, primer, pair or combination ofprimers, an enzyme or antibody, including an antibody fragment, which iscapable of detecting or aiding in the detection of a neurodegenerativedisease, as defined herein. The kit may comprise LysoTracker®, which isa fluorescent marker and is commercially-available from both Invitrogenand also Lonza. The LysoTracker® may be blue, blue-white, yellow, greenor red.

The kit also comprises acetyl-leucine or a pharmaceutically acceptablesalt thereof, as defined herein. The kit may further comprise buffers oraqueous solutions. The kit may further comprise instructions for usingthe acetyl-leucine or a pharmaceutically acceptable salt thereof in amethod of the invention.

In a further embodiment, there is disclosed acetyl-leucine, or apharmaceutically acceptable salt thereof, for use in a method ofproviding neuroprotection in a subject in need thereof (e.g., a subjecthaving, suspected of having, or at risk of having a neurodegenerativedisease).

“Neuroprotection” and its cognates, as used herein, refer to prevention,a slowing in, and/or a reversed progression of neurodegeneration,including, but not limited to, progressive loss of neuronal structure,progressive loss of neuronal function, and/or progressive neuronaldeath. Providing neuroprotection may result in delaying onset of aneurodegenerative disease or one or more symptoms of a neurodegenerativedisease that would otherwise be expected to manifest according totypical disease progression, reducing the severity of aneurodegenerative disease or reducing the severity of or eliminating oneor more existing symptoms associated with a neurodegenerative disease,delaying progression of a neurodegenerative disease or one or moresymptoms of a neurodegenerative disease over time as compared to typicaldisease progression, and/or reversing progression of a neurodegenerativedisease or one or more symptoms of a neurodegenerative disease overtime. The time over which neuroprotection is provided may coincide withthe duration of treatment as described herein. The treatment may provideneuroprotection over a duration of, for example, about seven days ormore, about two weeks or more, about three weeks or more, about onemonth or more, about six weeks or more, about seven weeks or more orabout two months or more. The treatment may provide neuroprotection overa duration of, for example, about three months or more, about fourmonths or more, about five months or more or about six months or more.It may provide neuroprotection over a duration of, for example, about 1year or more, about 2 years or more, about 3 years or more, about 4years or more, about 5 years or more, or about 10 years or more. Thetreatment may provide neuroprotection over the lifetime of the patient.

In another embodiment, a method of providing neuroprotection in asubject in need thereof (e.g., a subject having, suspected of having, orat risk of having a neurodegenerative disease) comprises administering atherapeutically effective amount of acetyl-leucine, or apharmaceutically acceptable salt thereof, to the subject.

Also disclosed is a kit for providing neuroprotection in a subject inneed thereof (e.g., a subject having, suspected of having, or at risk ofhaving a neurodegenerative disease), the kit comprising a means fordiagnosing or prognosing the disease/disorder, and acetyl-leucine or apharmaceutically acceptable salt thereof.

The present disclosure further includes the use of acetyl-leucine, or apharmaceutically acceptable salt thereof, as a neuroprotective agent ina subject in need thereof (e.g., a subject having, suspected of having,or at risk of having a neurodegenerative disease).

All of the features described herein (including any accompanying claims,abstract and drawings), and/or all of the steps of any method sodisclosed, may be combined with any of the above aspects in anycombination, except combinations where at least some of such featuresand/or steps are mutually exclusive.

EXAMPLES

The invention will now be explained in further detail in the followingExamples, which demonstrate the utility of acetyl-leucine in treating aneurodegenerative disease in a subject and providing neuroprotection insaid subject.

Example 1

In Vivo Mouse Study—Methods

Mouse Model

This study made use of an authentic mouse model of NPC, the Npc1^(−/−)(BALB/cNctr-Npc1^(m1N)) mouse, which is null for the NPC1 protein anddisplays all the hallmarks of the clinical disease (Loftus, 1997).

This mutant strain arose spontaneously and has a lifespan in the rangeof 10-14 weeks and therefore has a course of disease more acute that thevast majority of patients. The mutant mouse has been exploitedsuccessfully, not only for determining the ontogeny of disease andunderlying pathogenic mechanisms, but also for the evaluation ofexperimental therapies. Analyses using these mice have been undertakenat the whole animal, cellular, and molecular levels (Baudry, 2003;Smith, 2009; Cologna, 2014; Cologna, 2012). It is the most intensivelystudied animal model of NPC.

Prior to about 4-5 weeks of age Npc1^(−/−) mice have no discerniblebehavioural indication of disease that distinguishes them from wild-typelittermates. First indications of behavioural deficits, such as tremorand ataxic gait, appear by weeks 5-6; by weeks 7-8 defects in motorcoordination become more apparent, and by 9-10 weeks ataxia is advancedand accompanied by increased loss in weight and poor coat condition asfeeding and drinking becomes difficult (humane end point applied)(Smith, 2009).

Wild-type (Npc1^(+/+)) littermates were used as a control.

Treatment Protocol

A group of Npc1^(−/−) mice and a group of Npc1^(+/+) mice were treatedwith 0.1 g/kg acetyl-DL-leucine, provided mixed in the mouse chow, fromweaning (three weeks of age). Separate groups of Npc1^(−/−) andNpc1^(+/+) mice were left untreated, as controls.

Coat Condition

The coat condition of Npc1^(−/−) mice, with and withoutacetyl-DL-leucine treatment, was compared by simple observation of themice at nine weeks of age.

Weight Data

Animals were weighed twice a week. Weights were averaged (mean) acrossall mice in each group and compared.

Gait Analysis

Gait analysis was performed on mice at eight weeks of age using aCatWalk® 15.0 system according to manufacturer's instructions (Noldus,Nottingham, UK). Five runs were recorded per animal.

CatWalk® parameters measured were:

-   -   1. Stand Mean: average duration (s) of paws in contact with        glass plate;    -   2. Step Cycle: duration (s) between two consecutive contacts of        the same paw;    -   3. Duty Cycle: percentage of time paws in contact with plate        compared with time to complete a step cycle;    -   4. Step Sequence (AB): percentage of time spent walking in        LF-RH-RF-LH alternating pattern (LF: left front; RH: right hind;        RF: right front; LH left hind);    -   5. Cadence: step per seconds in a trial;    -   6. Diagonal Support: percentage of time with simultaneous        contact of diagonal paws with the glass plate (RF&LH or RH&LF).

Motor Function Analysis

Motor function analysis was performed on mice at eight and nine weeks ofage using an Open Field Activity Monitor according to manufacturer'sinstructions (Linton Instruments, Amlogger Software). Each mouse wasplaced in a plastic cage with bedding and analysed for five minutes.Rears were counted manually.

Motor function parameters measured were:

-   -   1. Centre Rearing: mice rearing on hind legs unsupported;    -   2. Rearing: mice rearing on hind legs with and without the        support of cage walls;    -   3. Activity: regular movement of the animal including walks;    -   4. Front to Back (FR) count: movement of the animal from front        to back of the cage;    -   5. Active Time: duration (s/min) of activeness regardless of        movement;    -   6. Mobile Time: duration (s/min) of mobility;    -   7. Rearing Time: duration of any rearing.

Results

Coat Condition

FIG. 1B shows an untreated Npc1^(−/−) age matched littermate. Npc1^(−/−)mice were observed as having poor coat condition at nine weeks of age,as feeding and drinking had become difficult (see FIG. 1B).

In distinct contrast, FIG. 1A shows an Npc1^(−/−) mouse treated withacetyl-DL-leucine from weaning. Npc1^(−/−) mice treated withacetyl-DL-leucine had a smooth and glossy coat, reminiscent of wild-type(Npc1^(+/+)) littermates (see FIG. 1A).

Weight Data

As can be seen in FIG. 2A, wild-type (Npc1^(+/+)) mice progressively puton weight for the duration of the study, i.e. from three weeks to 10weeks of age. Further, FIG. 2A shows the mean weight per group of miceat each point in time (Npc1^(−/−) untreated, n=1; Npc1^(−/−)acetyl-DL-leucine 0.1 g/kg, n=3; Npc1^(+/+) untreated, n=3; Npc1^(+/+)acetyl-DL-leucine 0.1 g/kg, n=2).

Treatment with acetyl-DL-leucine had no significant effect on thisweight gain.

Npc1^(−/−) mice initially put on weight, largely in the same manner asNpc1^(+/+) controls. However, the Npc1^(−/−) mice then began to loseweight from six weeks of age. At the end of the study (10 weeks of age),the mice weighed nearly as little as at just four weeks of age.

Treatment with acetyl-DL-leucine delayed these weight loss symptoms bytwo weeks compared to the untreated group.

A comparison of the weight changes in Npc1^(−/−) mice, with and withoutacetyl-DL-leucine treatment, is shown in FIG. 2B. In particular, FIG. 2Bshows the change in weight (%) per group of mice at each point in time,for the Npc1^(−/−) mice only. The beneficial effect of acetyl-DL-leucinetreatment in delaying weight loss is clearly evident from this Figure.

Gait Analysis

The results of the gait analysis are shown in FIG. 3. Diagonal support,cadence and step sequence data are shown in FIGS. 3A-3C, respectively.FIGS. 3D and 3E show front paw (FP) data (stand mean and step cycle inFIG. 3D; duty cycle in FIG. 3E). FIGS. 3F and 3G show hind paw (HP) data(stand mean and step cycle in FIG. 3F; duty cycle in FIG. 3G). Data arepresented as mean ±SEM. n=3 for Npc1^(+/+) untreated, n=2 for Npc1^(+/+)treated, n=i for Npc1^(−/−) untreated (hence no statistical analysisperformed), n=3 for Npc1^(−/−) treated.

The first bar in each graph shows the gait properties of wild-type(Npc1^(+/+)) mice.

The second bar in each graph shows the gait properties of wild-type(Npc1^(+/+)) mice treated with acetyl-DL-leucine. There was nosignificant difference in gait properties between these mice and theiruntreated littermates.

The third bar in each graph shows the gait properties of an Npc1^(−/−)mouse. On the whole, this mouse showed poor gait compared to Npc1^(+/+)mice. The mouse spent extremely little time, if any, in diagonal support(FIG. 3A) or step sequence (FIG. 3C), and its hind paw function in standmean (FIG. 3F) and duty cycle (FIG. 3G) were also drastically hindered.

The fourth bar in each graph shows the gait properties of Npc1^(−/−)mice treated with acetyl-DL-leucine. These mice demonstratedsignificantly improved gait compared to their untreated littermates. Infact, they showed similar gait properties to Npc1^(+/+) mice.

Motor Function Analysis

Analysis at eight weeks of age revealed no difference in motor functionproperties between Npc1^(−/−) and wild-type (Npc1^(+/+)) mice (data notshown).

By nine weeks of age, however, defects in motor coordination had becomeapparent.

The results of the motor function analysis at nine weeks are shown inFIG. 4. Centre rearing, activity, rearing and front to back (FR) countare shown in FIGS. 4A-4D, respectively. Active time, mobile time,rearing time and total manual rearing count are shown in FIGS. 4E-4H,respectively. Data are presented as mean ±SEM. n=3 for Npc1^(+/+)untreated, n=2 for Npc1^(+/+) treated, n=1 for Npc1^(−/−) untreated(hence no statistical analysis performed), n=3 for Npc1^(−/−) treated.

The first bar in each graph shows the motor function properties ofwild-type (Npc1^(+/+)) mice.

The second bar in each graph shows the motor function properties ofwild-type (Npc1^(+/+)) mice treated with acetyl-DL-leucine. There was nosignificant difference in motor function properties between these miceand their untreated littermates.

The third bar in each graph shows the motor function properties of anNpc1^(−/−) mouse. On the whole, this mouse showed poor motor functioncompared to Npc1^(+/+) mice. The mouse spent extremely little time, ifany, rearing (panel H), particularly on its hind legs unsupported (panelA).

The fourth bar in each graph shows the motor function properties ofNpc1^(−/−) mice treated with acetyl-DL-leucine. These mice demonstratedsignificantly improved motor function compared to their untreatedlittermates. In fact, they showed similar motor function properties toNpc1^(+/+) mice.

Lifespan

It was also observed that treatment of the Npc1−/− mouse withacetyl-DL-leucine (0.1 g/kg from 3 weeks of age) is associated with astatistically significant increase in lifespan (FIG. 5). This datafurther indicates the effect of acetyl-leucine in delaying the onset ofthe disease.

Conclusion

Where Npc1^(−/−) mice had discernible indication of disease thatdistinguished them from wild-type littermates from 5-6 weeks of age,Npc1^(−/−) littermates treated with acetyl-DL-leucine from weaning didnot display such symptoms until two or more weeks later. Treatment ofNpc1^(−/−) mice with acetyl-DL-leucine delayed onset and progression ofNPC symptoms and showed evidence of neuroprotection.

It is reasonable to expect that, as acetyl-DL-leucine provided generalneuroprotection, that the results observed in NPC will also be observedin other neurodegenerative disorders, and neurodegenerative disordersthat are associated with defects in lysosomal storage.

Example 2

Methods

A fibroblast cell line from an NPC patient was treated for 3 days withN-acetyl-DL-leucine (1 mM) and relative lysosomal volume was quantifiedvia LysoTracker, a fluorescent dye that accumulates in acidicorganelles. Increased LysoTracker fluorescence is indicative of anincrease in lysosomal size and/or number, and is a hallmark of NPCcells.

In addition, fibroblasts derived from Niemann-Pick A (NPA),Mucolipidosis Type II (MLII), Mucopolysaccharidosis Type IIIB (MPSIIIB), Aspartylglucosaminuria, Mucolipidosis Type IIIA (MLIIIA), andMucopolysaccharidosis Type VII (MPS VII) patients were treated withacetyl-DL-Leucine (1 mM) for 6 days and lysosomal volume was quantifiedvia LysoTracker.

Results

Treatment of fibroblasts derived from an NPC patient of mild clinicalseverity with 1 mM N-acetyl-DL-leucine was associated with a significantdecrease in LysoTracker fluorescence, indicative of reduced lysosomalvolume over time (FIG. 6A). These findings were replicated infibroblasts obtained from additional NPC patients of variable clinicalseverity that were treated with 1 mM N-acetyl-DL-leucine for 72 hours(FIG. 6B).

Fibroblasts derived from NPA, and MLII, MPS IIIB,Aspartylglucosaminuria, MLIIIA, and MPS VII patients were observed tohave elevated LysoTracker fluorescence levels relative to age-matchedwild-type controls (FIGS. 6C-6H). This is indicative of an expandedlysosome occurring as a result of lipid storage compared to fibroblastsfrom healthy individuals. Treatment with acetyl-leucine was associatedwith a statistically significant reduction in LysoTracker fluorescencetoward control level in both the NPA, and MLII, and MPS IIIB fibroblastsrelative to untreated NPA, and MLII, and MPS IIIB fibroblasts,respectively (FIGS. 6C-6E), and was associated with a trend in reducingLysoTracker fluorescence toward control level in theaspartylglucosaminuria, MLIIIA, and MPS VII fibroblasts relative tountreated aspartylglucosaminuria, MLIIIA, and MPS VII fibroblasts,respectively (FIGS. 6F-6H). The reduction in LysoTracker fluorescencewas indicative of a decrease in lysosomal volume (FIGS. 6C-6H and 6D).Data presented in FIGS. 6A-6D show the results after 6 days of thetreatment for each cell line, respectively with 1 mM acetyl-leucine,with lysosomal volume expressed as fold change relative to untreatedwild-type fibroblasts. The asterisks (*/****) indicates a p-values of(<0.05/0.001) versus untreated disease fibroblasts.

Conclusion

N-acetyl-DL-leucine treatment was associated with the rectification ofdisturbed lysosomal storage by reducing lysosomal volume and thusacetyl-leucine directly corrected a phenotype of these lysosomal storagedisorders. These diseases represent different classes of LSDs, and thusthese results further support utility of acetyl-leucine's effect againsta broad range of lysosomal storage disorders.

Example 3

Sandhoff disease is a disorder which may result from the autosomalrecessive inheritance of mutations in the HEXB gene, which encodes thebeta-subunit of beta-hexosaminidase. As a result of this, GM2ganglioside fails to be degraded and accumulates within lysosomes incells of the periphery and the central nervous system (CNS).

This study made use of a mouse model of Sandhoff disease, the Hexb^(−/−)mouse, as described in Jeyakumar et al. (Jeyakumar, M. et al. (1999)Proc. Natl. Acad. Sci. USA 96: 6388-6393).

Wild-type (Hexb^(+/+)) mice were used as controls.

Lifespan

Treatment with acetyl-DL-Leucine was associated with a statisticallysignificant increase in the lifespan of the Sandhoff mouse (FIG. 7A). InFIG. 7A, acetyl-leucine-treated mice were treated with 0.1 g/kgacetyl-leucine from 3 weeks of age. The asterisks (*) indicates ap-value of <0.05 vs untreated Sandhoff mice. Data is average of n=6 miceper group. Without treatment, the median survival time of Sandhoff micewas 112 days. Treatment with acetyl-leucine (0.1 g/kg body weight since3 weeks of age) increased the median lifespan to 120 days.

Motor Function

Treatment of Sandhoff mice with acetyl-leucine gave rise to improvementsin motor function as indicated by bar crossing and step cycle studies.

Bar Crossing Test

The bar crossing test is a method for assessing motor function in micein which the mouse is placed hanging from the centre of a horizontal barby its front limbs. A wild-type mouse with normal motor function will beable to engage its hind limbs and thereby move to one of the platformsat either end of the bar, and in doing so complete the test.

An untreated Sandhoff mouse is able to complete the test up until aroundii weeks of age. After this point motor function and hind-limbmobility/engagement have deteriorated to the point to which the mousecannot complete the test, and will drop from the bar onto the paddedsurface below.

Treatment of the Sandhoff mouse model with acetyl-DL-leucine (0.1 g/kgbody weight from 3 weeks of age) was associated with improved motorfunction and hind-limb mobility/engagement as assessed via thebar-crossing test (FIG. 7B). In FIG. 7B, acetyl-leucine treatment of 0.1g/kg body weight was provided from 3 weeks of age. The acetyl-leucinetreated Sandhoff mice retained the ability to complete the test up to 13weeks of age (inclusive). Data shown is the mean of 6 mice per group.The treated Sandhoff mice retained the ability to complete the test upto 13 weeks of age (inclusive).

Step Cycle

Step cycle is the length of time taken during locomotion by a limb fromthe time it leaves the ground until it leaves the ground on the nextoccasion.

Step cycle time was assessed at 12 weeks of age in untreated andacetyl-leucine treated Sandhoff model mice. Acetyl-leucine treatmentconstituted 0.1 g/kg body weight acetyl-leucine from 3 weeks of age.

Treatment of the Sandhoff mouse model with acetyl-leucine was associatedwith significantly faster front step cycle times (p<0.05 vs untreated SHmouse), significantly faster hind step cycle times (p<0.01 vs untreatedSH mouse) and significantly faster average step cycle times (p<0.001 vsuntreated SH mouse) (FIG. 7C). In FIG. 7C, Acetyl-leucine treatment of0.1 g/kg body weight was provided from 3 weeks of age. Front step cyclerefers to the mouse's front limbs, hind step cycle to the mouse's rearlimbs, and average step cycle takes into account all of the mouse'slimbs. The asterisks (*/**/***) indicate p-values of \<0.05/0.01/0.001versus untreated Sandhoff mouse. Data shown is mean ±Stdev.

Thus, acetyl-leucine treatment was associated with a faster step cyclein the Sandhoff mouse model, which may indicate improvement in motorfunction.

Conclusions

These studies demonstrate that acetyl-leucine treatment of a mouse modelof Sandhoff disease may give rise to improvements in motor function asassessed by two independent experiments, as well as significantlyincreased lifespan.

Example 4

GM2 gangliosidoses are a group of lysosomal storage disorders arisingfrom defects in β-hexosaminidase activity. The group encompassesTay-Sachs disease, Sandhoff disease, and the AB variant of Tay-Sachsdisease.

Fibroblasts derived from GM2 patients (Tay-Sachs disease, Sandhoffdisease, and the AB variant of Tay-Sachs disease) and healthy controlswere treated with acetyl-DL-leucine (1 mM for 6 days) prior toextraction and quantification of glycosphingolipid (GSL) levels via highperformance liquid chromatography (HPLC).

In the absence of treatment, fibroblasts derived from all 3 varieties ofGM2 gangliosidosis demonstrated elevated GSL levels when compared tountreated wild-type controls. In all 3 cases, treatment withacetyl-DL-leucine (1 mM for 6 days) was associated with a reduction inGSL storage. In the case of Tay-Sachs disease, this decrease wasstatistically significant (p<0.05). In the case of Sandhoff disease andthe AB variant of Tay-Sachs, there was a trend towards decreased GSLlevels associated with treatment. Data presented in FIGS. 8A-8C show theresults of the treatment for each cell line, respectively, with GSLlevels adjusted for protein content and expressed as fold changerelative to levels in untreated wild-type fibroblasts.

Example 5

Patient 1

The patient in this case study was a 28 year-old male who wasgenetically diagnosed with Tay-Sachs disease and who exhibiteddysarthrophonia, tremor, ataxia of stance and gait, paraparesis andmuscle atrophies. In particular, the patient was not able to stand orwalk, could do single steps with strong support, and had distinctpostural instability, ocular movement disorder, dysphagia anddysarthria, and mild cognitive function disorder. First symptoms wereobserved at the age of 16 years.

Before treatment was commenced, examination of the patient indicated aScale for Assessment and Rating of Ataxia (SARA) score of 15.5/40. Inaddition, results from the patient's Spinocerebellar Ataxia FunctionalIndex (SCAFI) analysis were:

-   -   Mean 8-meters Walking Test (8MW): 21.6 s    -   MW 9-Hole Pegboard Test Dominant (9HPTD) (right): 48.3 s    -   MW 9-Hole Pegboard Test Non-Dominant (9HPTND): 44.9 s    -   MW PATA Word Test: 20    -   Montreal Cognitive Assessment (MoCA): 18/30

Video of the patient was also recorded for later comparison.

The day following this examination, the patient was started on therapywith acetyl-leucine, at a dose of 3 g per day for the first week,followed by a dose of 5 g per day for the second week onwards.

After one month and four months, respectively, the patient wasre-examined while continuing treatment. After one month, the patient hadimproved fine motor skills and reduced hand tremor, for example whileeating or drinking. Walking was not markedly changed. After four months,the patient was in stable condition with slightly improved cognitivefunction but had deterioration of stance, gait and fine motor function.The patient's SARA scores and results from the patient's SCAFI analysesare shown below compared to baseline.

TABLE 1 Patient Evaluation Parameters After one month with After 4months with Baseline acetyl-DL-leucine acetyl-DL-leucine SARA 15.5/40  15.5/40   17/40 8MWT 21.6 sec   7 sec 25.49 sec 9HPTD 48.3 sec 45.9 sec48.67 sec 9HPTND 44.9 sec 40.1 sec 47.09 sec PATA 20 22 21 MoCA 18/3021/30 22/30

Overall, the patient exhibited an improvement in symptoms followingacetyl-leucine treatment.

Patient 2

The patient in this case study was a 32 year-old female who wasgenetically diagnosed with Tay-Sachs disease and who exhibited ataxia ofstance and gait, fine motor impairment, paraparesis of lowerextremities, and muscle atrophies. In particular, walking was notpossible without support, and the patient suffered from dysphagia andspeech disorder, ocular movement disorder, and mild cognitive functiondisorder. First symptoms were observed at the age of 7 years.

Before treatment was commenced, examination of the patient indicated aScale for Assessment and Rating of Ataxia (SARA) score of 10.5/40. Inaddition, results from the patient's Spinocerebellar Ataxia FunctionalIndex (SCAFI) analysis were:

-   -   Mean 8-meters Walking Test (8MW): 12.5 s    -   MW 9-Hole Pegboard Test Dominant (9HPTD) (right): 21.5 s    -   MW 9-Hole Pegboard Test Non-Dominant (9HPTND): 35.5 s    -   MW PATA Word Test: 18    -   Montreal Cognitive Assessment (MoCA): 21/30

Video of the patient was also recorded for later comparison.

The day of the examination, the patient was started on therapy withacetyl-leucine at a dose of 3 g per day for the first week, followed bya dose of 5 g per day for the second week onwards.

After one month, the patient was re-examined while continuing treatmentand showed increased enunciation, improved postural stability, andenhanced cognitive function. Stance and gait were possible withoutsupport. The patient's SARA score and results from the patient's SCAFIanalysis are shown below compared to baseline.

TABLE 2 Patient Evaluation Parameters After one month with Baselineacetyl-DL-leucine SARA 10.5/40    5/40 8MWT 12.5 sec  9.55 sec 9HPTD21.5 sec 34.97 sec 9HPTND 35.5 sec 39.34 sec PATA 18 17 MoCA 21/30 25/30

Patient 3

The patient in this case study was an 8 year-old male who wasgenetically diagnosed with Tay-Sachs disease and who had epilepticcramps (tonic-clonic, about 10 seconds, self-limiting) almost every daybefore falling asleep, ocular movement disorder, anarthria, distinctproblems in cognitive function and concentration (neurologicalexamination was not possible), was not able to stand or walk by himself,and was very limited in daily activities (eating, washing or dressinghimself was not possible). First symptoms were observed at the age of 9months.

Before treatment was commenced, examination of the patient indicated aScale for Assessment and Rating of Ataxia (SARA) score of 36/40, a mRDSscore of 18/24, a EQ-5D-5L visual scale of 50, and a 8MWT of 18.1 (onlywith strong support).

The patient was started on therapy with acetyl-leucine at a dose of 1.5g per day for the first week, followed by a dose of 3 g per day for thesecond week onwards.

After one month, the patient was re-examined while continuing treatmentand showed increased fine motor skills (was able to grab small things),increased motivation (tried more often to walk by himself), improvedpostural stability, gait and stance, and could speak single words. Thepatient's SARA, mRDS, EQ-5D-5L visual scale, and 8MWT scores are shownbelow compared to baseline.

TABLE 3 Patient Evaluation Parameters After one month on Baselineacetyl-DL-leucine SARA 36/40 33/40 mRDS 18/24 16/24 EQ-5D-5L visualscale 50 60 8MWT 18.1 (only with 11.75 (with support strong support) ofone arm)

Example 6

The patient in this case study was a 13 year-old male who wasgenetically diagnosed with GM1 Gangliosidosis and who was not able tostand or walk by himself, was very limited in daily activities (eating,washing, dressing himself was not possible), and had ocular movementdisorder, anarthria, and distinct problems in cognitive function andconcentration (neurological examination was not possible). Firstsymptoms were observed at the age of 2 years.

Before treatment was commenced, examination of the patient indicated aScale for Assessment and Rating of Ataxia (SARA) score of 35/40, a mRDSscore of 15, and a EQ-5D-5L visual scale of 50.

The patient was started on therapy with acetyl-leucine at a dose of 1.5g per day for the first week, followed by a dose of 3 g per day for thesecond week onwards.

After one month, the patient was re-examined while continuing treatmentand showed a stable general condition, increased gait (more fluent), andstable stance in natural position. The patient's SARA, mRDS, andEQ-5D-5L visual scale scores are shown below compared to baseline.

TABLE 4 Patient Evaluation Parameters After one month on Baselineacetyl-DL-leucine SARA 35/40 35/40 mRDS 15 16 EQ-5D-5L visual scale 5060

Example 7

Patient 1

The patient in this case study was a 73 year-old male who had previouslybeen diagnosed with amyotrophic lateral sclerosis (ALS).

The patient's symptomatology was characterised by progredient dysarthria(nasal and slurred speech) and weakness of the right dorsiflexor withconsequent foot drop over the course of the previous three years.

Clinically, the patient showed bulbar speech, a 3/5 paresis of the rightfoot-dorsiflexors and big toe-lift, generalised exaggerated reflexes andspastic tone increase of the right lower limb. EMG showed spontaneousactivity and cMRT did not show any pathology.

The patient was started on medication with Riluzol around the time ofALS diagnosis. However, the clinical symptomatology remained unchanged.

The patient was then started on therapy with acetyl-DL-leucine, at adose of 3 gram per day for the first week, then a dose of 5 gram per dayfor the second week onwards. The results were documented by video.

After 15 days of treatment, a medical examination was conducted in whichthe patient reported significant improvement of speech. The patient wasable to speak more fluently and was able to modulate his voice bettercompared to pre-medication (which was documented by video).

After a further 20 days, a further medical examination was conducted inwhich the patient reported further improvement of speech. In addition,the patient reported improvement of gait. The paresis of the rightfoot-dorsiflexors and consequently the foot drop had improveddramatically and were clinically hardly detectable. In addition, thepatient reported an improvement in sleep: falling asleep much quicker,sleeping longer and feeling clearly more rested in the morning.

The patient continued on the treatment for approximately another 30days. About 7 days after the patient stopped treatment, a medicalexamination was conducted in which the patient reported no furthersubjective improvement of either speech or paresis of the rightdorsiflexor. Sleep had also deterioriated. After about 1-2 additionalweeks off the acetyl-leucine treatment, the patient reporteddeterioration of speech. The patient resumed treatment at that time and,about two months later, reported stable symptomatology. Compared to theat the time when acetyl-leucine treatment was first initiated, a slightdeterioration of speech could be observed.

As the patient had not observed any improvement of speech, the patientasked to stop the medication. Approximately 2-3 weeks later, the patientagain reported deterioration of speech after discontinuation ofacetyl-DL-leucine treatment. The patient resumed treatment and reportedimproved symptomatology, in particular speech.

Overall, the patient exhibited an improvement in symptoms followingacetyl-leucine treatment.

Patient 2

The patient in this case study was a 74 old male who had been previouslydiagnosed with ALS.

The patient's symptomatology was characterised by progredient dysarthria(nasal and slurred speech) and concomitant dysphagia, and weakness whilewalking for over a year, and a paresis of the left upper limb forapproximately four months. EMG had shown generalised polyphasic activityand chronic neurogenic impairment in the bulbar, cervical and lumbarsegment.

Clinical examination of the patient showed severe dysarthria,hypomotility of the tongue, 2/5-3/5 paresis of the left arm withimpairment of fine motor skills, generalised exaggerated reflexes andfasciculations. Medication with Riluzol had been started one monthearlier.

The patient was started on treatment with acetyl-DL-leucine, at a doseof 3 g per day for the first week, then a dose of 5 g per day for thesecond week onwards.

After approximately 2 months, the patient was re-examined and hereported progredient deterioration of the motor function of the lefthand, but a discrete improvement of walking. In addition, swallowingfunctions have remained stable.

Patient 3

The patient in this case study was a 66 year old male who had beenpreviously diagnosed with ALS.

The patient's symptomatology was characterized by progredient weaknessand atrophy of both proximal upper extremities, slight impairment offine motor skills, and generalized fasciculations and cramps. EMG hadshown pathologic spontaneous activity and chronic neurogenic change, MRTof the brain and cervical column did not show any pathology. Medicationwith Riluzol was started.

About two months later, a clinical examination showed a 3/5 to 4/5paresis of both shoulders and proximal arms and a slowing of fine motorscills, generalized fasciculations, and normal reflexes. The patient wasstarted on treatment with acetyl-DL-leucine, at a dose of 3 g per dayfor the first week, then a dose of 5 g per day for the second weekonwards.

After one month, the patient did not report improvement ofsymptomatology, with no improvement of muscle force of upper limbs.Medication with acetyl-DL-leucine was suspended and the patient wasasked to report worsening of symptomatology.

Patient 4

The patient in this case study was a 66 year old male who had beendiagnosed with ALS. The patient's symptomatology was characterized byprogressive weakness and atrophy of both proximal upper extremities,slight impairment of fine motor skills, and generalized fasciculationsand cramps. EMG showed pathologic spontaneous activity and chronicneurogenic change. MRT of the brain and cervical column did not show anypathology. Treatment with riluzole was started.

A clinical examination showed a 3/5 to 4/5 paresis of both shoulders andproximal arms, a slowing of fine motor scills, generalizedfasciculations, and normal reflexes, and an ALS-FRS score of 44/48.

The patient was started on treatment with acetyl-DL-leucine, at a doseof 3 g per day for the first week, then a dose of 5 g per day for thesecond week onwards.

After about one month, the patient reported subjective improvement ofdysphagia and less hypersalivation. His relatives reported improved andmore vital facial expression. Weakness of limbs was unchanged. Therapywas suspended and, 10 days later, the patient reported worsening ofsymptomatology, particularly subjective deterioration of dysphagia andhypersalivation. The patient resumed continuous treatment.

The patient was re-evaluated about 8 weeks later and symptomatologyremained stable. The patient's ALS-FRS score was 43/48. Compared tosymptomatology around the time of diagnosis, there was only a slightprogression of weakness of gait and upper limbs.

Example 8

Acetyl-leucine treatment was demonstrated to give rise to improvementsin 3 patients who had been diagnosed with multisystemic atrophycerebellar type (MSA-C).

Patient 1

Patient 1 in this case study was a female in her late 50s who had shownprogressive ataxia with speech problems and walking problems for theprevious three years.

Clinical examination of the patient revealed central cerebellar ocularmotor signs, moderate dysarthrophonia, mild limb ataxia, and moderateataxia of stance and gait. Furthermore, a MRI of the patient showedatrophy of the cerebellum and the brainstem, in particular of the ponsand mesencephalon. The patient was accordingly diagnosed as havingMSA-C.

The patient was started on treatment with acetyl-DL-leucine, at a doseof 5 g per day (2 g upon waking, 1.5 g prior to lunch and 1.5 g prior tothe evening meal).

After one week of treatment the patient already showed a significantimprovement in speech.

Patient 2

The patient in this case study was a 77 year-old male who had beendiagnosed with MSA-C.

The patient's symptomatology was characterised by progressivedifficulties of walking and insecure gait with a tendency to fall (thepatient fell approximately 10 times a month). The patient exhibiteddizziness, hypokinetic-rigid syndrome, saccadic eye movements, dysmetriain the coordination test, and autonomic dysfunction, for exampleerectile dysfunction, orthostatic hypotension and incomplete bladderemptying over the course of the last four years.

Before treatment was commenced, the patient's symptoms remainedunchanged over at least a three-month period.

The patient was started on treatment with acetyl-DL-leucine at a dose of3 gram per day for the first week, followed by a dose of up to 5 gramper day.

After 3 weeks of treatment, a further examination was carried out. Thepatient and his wife reported significant improvement of gait: thepatient walks more securely and the falls completely stopped. Inaddition, dizziness experienced by the patient substantially improved.

The patient was instructed to stop the medication and after one week thepatient reported a deterioration of gait and dizziness. The patientreported feeling more insecure walking, with a strong tendency to fall.

The patient was then instructed to restart the medication, which hecontinued for a further 40 days and then again stopped. During clinicalexamination 7 days after stopping the medication, the patient confirmedprogressive deterioration of gait and dizziness two days after stoppingthe treatment, and a very strong tendency to fall 5 days after stoppingthe treatment. The patient subsequently returned to continuoustreatment.

Patient 3

The patient in this case study was a 76 year-old male who had beendiagnosed with oligosymptomatic MSA-C.

The patient's symptomatology was characterised by progressivedifficulties in walking and insecure gait (without falls), as well asdizziness.

Clinically, the patient showed saccadic eye movement and dysmetria inthe coordination tests. cMRI showed an atrophy of the mesencephalon, andFDG-PET of the brain showed a reduced metabolism of the striatum andcerebellum. The patient's posturography test results were pathologicalwith a high tendency to fall.

Before treatment was commenced, the patient's clinical symptomatologyremained unchanged over at least a one-year period.

Gait analysis was performed, which showed atactic gait, and reducedspeed and increased track width compared to the normal range, andfluctuations of gait. The patient was then started on treatment withacetyl-DL-leucine at a dose of 3 gram per day for the first week,followed by a dose of 5 gram per day for the second week onwards.

After one month of treatment, a further examination was carried out.Gait analysis showed an improvement of gait speed, and reductions oftrack width and gait fluctuations.

TABLE 5 Gait analysis parameters. Shortly after commencing After 27 daysNormal range treatment of treatment (± SD) Speed (cm/sec) 72 106 110.81(18.33) Max. speed(cm/sec) 183 208 158.30 (22.66) Cadence(steps/minute)101 113 109.19 (12.75) Track width (cm) 16.8 14.6 9.06 (1.94) Step cyclelength(cm) 87 113 121.81 (11.52) Double stance (%) 32.5 27.3 20.73(2.55) Coefficient of 3.3 3.1 1.94 (0.85) variation (temporal)Functional Gait 21/30 20/30 24.9 (3.6) Assessment

The patient was instructed to stop the medication and he reportedprogressive deterioration of gait and dizziness approximately two tothree weeks after stopping the medication.

The patient subsequently returned to continuous treatment andsymptomatology re-improved. Treatment was again suspended and thepatient was evaluated three weeks later. The patient reporteddeterioration of symptoms, especially dizziness. Gait analysis showed anincreased gait width comparable to pre-therapy status:

TABLE 6 Gait analysis parameters. After 20 days of re-suspendingtreatment Speed (cm/sec) 106 Max. speed (cm/sec) 197 Cadence(steps/minute) 112 Track width (cm) 17.5 Step cycle length (cm) 115Double stance (%) 27.1 Coefficient of variation (temporal) 2.5Functional Gait Assessment 22/30

Example 9

The patient in this case study was a 59 year-old male with progredientpersonality change characterised by apathy, lethargy and indifference.In addition, the patient showed a mainly left-side hypokinetic-rigidsyndrome with impairment of fine motor skills and reduced resonation ofleft arm. Furthermore, the patient showed generalised bradykinesia andgait disorder with small steps and 2-3 falls per month. The patient alsoshows slurred speech and cognitive deficits concerning psychomotoricslowing and reduced semantic word fluency.

The patient was diagnosed with frontotemporal dementia with parkinsonismand Datscan revealed a reduction of dopamine receptors supporting thediagnosis. FDG-PET of the brain showed a mainly frontal reducedmetabolism.

The patient exhibited little improvement during treatment with L-Dopaand Ropinirol.

The patient was started on treatment with acetyl-DL-leucine, at a doseof 3 gram per day for one week, then a dose of 5 gram per day for 4weeks.

After approximately one month of acetyl-leucine treatment, medicationwas stopped and the patient was re-examined 13 days later.

The patient and his wife and daughter reported a significant improvementof gait under therapy with acetyl-leucine and in addition the patient'sfalls stopped. The patient also exhibited an improvement of speech,which was less slurred, more comprehensible and subjectively much morecontrolled. After suspension of treatment the symptoms worsened.

Example 10

The patient in this case study was a 75 year-old male with progressiveinsecure gait disorder and dizziness leading to backward falls. Inaddition, the patient presented a mainly left-sided hypokinetic-rigidsyndrome with apraxia and alien-limb phenomenon.

The patient was diagnosed with corticobasal syndrome. A Datscan revealeda reduction of dopamine-receptors and an MRI showed an atrophicmotorcortex of the right hemisphere supporting the diagnosis.

The patient exhibited no improvement during treatment with L-Dopa.

The patient was started on treatment with acetyl-DL-leucine, at a doseof 3 g per day for the first week, then 5 g per day. Gait analysis wasperformed before treatment commenced.

After 20 days of acetyl-leucine treatment, the patient was re-examined.An improvement of dizziness symptoms and significant reduction in thefrequency of falls was noted.

TABLE 7 Gait analysis parameters. Before After 20 days treatment oftreatment Mean (±SD) Speed (cm/sec) 63 92 110.81 (18.33) Max. speed(cm/sec) 131 152 158.30 (22.66) Cadence 90 106 109.19 (12.75)(steps/minute) Track width (cm) 12.1 12.3  9.06 (1.94) Step cycle length(cm) 84 104 121.81 (11.52) Double stance (%) 29.8 26.6  20.73 (2.55)Coefficient of variation (temporal) 3.9 3.4  1.94 (0.85) Functional GaitAssessment 13/30 18/30  24.9 (3.6)

There was an objective improvement in gait analysis parameters, forexample in speed, maximal speed, cadence and reduced double stance(Table 2 and FIG. 9).

After 8 weeks of acetyl-leucine treatment, medication was stopped andthe patient was re-examined 6 days later.

The patient reported an increase of dizziness symptoms two days aftersuspension of treatment (the sensation of being drunk).

The patient subsequently returned to continuous treatment.

Example 11

Patient 1

The patient in this case study was a 76 year-old female with dizziness,which mainly occurred while walking. No falls were reported. The patientalso exhibited gait disorder with small steps and generalisedbradykinesia and vertical gaze palsy with impairment of fine motorskills.

The patient was diagnosed with progressive supranuclear palsy. Datscanrevealed a reduction of dopamine-receptors and FDG-PET of the brainshowed a mainly frontal reduced metabolism, supporting the diagnosis.

The patient exhibited little improvement during treatment with L-Dopa.

The patient was started on treatment with acetyl-DL-leucine, at a doseof 3 g per day for one week, then a dose of 5 g per day for 4 weeks.After 27 days of acetyl-leucine treatment, medication was stopped andthe patient was re-examined 60 days later.

The patient reported a significant reduction of dizziness and slightimprovement of gait under therapy with acetyl-leucine. After suspensionof treatment, the symptoms worsened.

The patient was re-examined about two months later and reported a stablesymptomatology of underlying progressive supranuclear palsy; there wasno clinical progression. The PSPRS Score remained stable, and thereduction of dizziness was still significant.

Patient 2

The patient in this case study was a 66 year-old female with symmetrichypokinetic-rigid syndrome, gait disorder with insecure and small steps(strong tendency to fall) and vertical gaze palsy with impairment offine motor skills. The patient was diagnosed with progressivesupranuclear palsy. Datscan revealed a reduction of dopamine-receptorsand FDG-PET of the brain showed a mainly frontal reduced metabolism,supporting the diagnosis. There was no levodopa response.

The patient was started on treatment with acetyl-DL-leucine, at a doseof 3 g per day for the first week, then 5 g per day. Gait analysis wasperformed before treatment commenced. After 17 days of treatment,medication was stopped and the patient was re-examined 4 days later. Thepatient reported no significant improvement of gait or hypokinetic rigidsyndrome.

TABLE 8 Gait analysis parameters. Before After 17 days Normal values —treatment of treatment (±SD) speed (cm/sec) 51 68 119.12 (17.27) Max.speed (cm/sec) 123 98 176.78 (19.10) cadence (steps/minute) 93 99 113.06(10.38) Track width (cm) 10.3 9.3  9.49 (3.56) Step cycle length (cm) 6682 126.71 (13.06) Double stance (%) 34.5 28.6  20.35 (3.21) Coefficientof variation 8.5 6.6  1.76 (0.73) (temporal) Functional Gait Assessment15/30 15/30  27.1 (2.3)

The patient was reevaluated about two months later and reported nodeterioration of symptoms after stopping medication.

Patient 3

The patient in this case study was a 56 year-old male with symmetrichypokinetic-rigid syndrome, insecure and history of falls and verticalgaze palsy with impairment of fine motor skills. The patient wasdiagnosed with progressive supranuclear palsy. Datscan revealed areduction of dopamine-receptors and FDG-PET of the brain showed afrontomesial and parietotemporal reduced metabolism, supporting thediagnosis. There was no levodopa response.

The patient was started on treatment with acetyl-DL-leucine, at a doseof 3 g per day for the first week, then 5 g per day. Gait analysis wasperformed before treatment commenced. After 17 days of treatment,medication was stopped and the patient was re-examined 4 days later. Thepatient reported no significant improvement of gait or hypokinetic rigidsyndrome.

TABLE 9 Gait analysis parameters. Before After 17 days Normal values —treatment of treatment (±SD) speed (cm/ sec) 103 120 125.34 (20.66) Max.speed (cm/sec) 163 194 180.07 (26.57) cadence (steps/minute) 106 112115.27 (12.02) Track width (cm) 15.5 15.1  9.12 (2.97) Step cycle length(cm) 118 129 130.34 (13.01) Double stance (%) 25.8 24.3  19.65 (2.75)Coefficient of variation 3.6 3.1  1.77 (1.04) (temporal) Functional GaitAssessment 28/30 27/30  28.4 (1.6)

The patient was reevaluated about two months later and reported nodeterioration of symptoms after stopping medication.

Patient 4

The patient in this case study was a 76 year-old male with progredientgait disorder, insecure and small steps (strong tendency to fall),camptocormia, slow and hypometric saccades, blepharospasmus andimpairment of fine motor skills. The patient was diagnosed withprogressive supranuclear palsy. MRI showed discreet atrophy of the midbrain (Mickey Mouse sign). There was a slight levodopa response.

The patient was started on treatment with acetyl-DL-leucine, at a doseof 3 g per day for the first week, then 5 g per day. Gait analysis wasperformed before treatment commenced. After three weeks of treatment,medication was stopped and the patient was re-examined. The patientreported gait with increased subjective security and with reducedfrequency of falls. Gait analysis showed improvement of gait withincreased speed, max. speed, and step cycle length and reduction oftrack width, double stance and coefficient of variation.

TABLE 10 Gait analysis parameters. Before After 3 weeks of Normal valuestreatment treatment (±SD) speed (cm/sec) 39 65 110.81 (18.33) Max. speed(cm/sec) 70 93 158.30 (22.66) cadence (steps/minute) 109 125 109.19(12.75) Track width (cm) 15.4 13.6  9.06 (1.94) Step cycle length (cm)43 63 121.81 (11.52) Double stance (%) 45.4 36  20.73 (2.55) Coefficientof variation 8.2 6.8  1.94 (0.85) (temporal) Functional Gait Assessment14/30  24.9 (3.6)

After three months without medication, the patient reported aprogression of hypokinetic-rigid syndrome. Gait worsened, with morefrequent falls.

Example 12

Patient 1

The patient in this case study was a 42 year-old male engineer who hadsuffered from dizziness and postural imbalance for almost one year.

The patient was diagnosed with downbeat nystagmus: the patient wasseverely impaired by blurred vision (oscillopsia) due to the nystagmus,and experienced difficulties while reading and writing. The patient'svisual acuity was: right 0.75, left 0.67, binocular 0.83, and thedownbeat nystagmus was documented by video-oculography. The patient alsoexhibited increased body sway, which was documented by posturography.

Treatment with 4-aminopyridine (Fampyra, 10 mg twice daily) for fourweeks did not give rise to any benefit.

The patient was started on treatment with acetyl-DL-leucine, at a doseof 3 g per day (1 g upon waking, 1 g prior to lunch and 1 g prior to theevening meal) for one week, then a dose of 5 gram per day (2 g uponwaking, 1.5 g prior to lunch and 1.5 g prior to the evening meal).

After 10 days, the patient reported significant benefit and that theeffect developed slowly. The patient continued with this treatmentdosage, and no side-effects resulted. A temporary suspension of themedication led to a considerable deterioration.

The patient was re-examined approximately 14 weeks after startingacetyl-leucine treatment, during which the patient reported to be veryhappy with the benefit. The patient's reading and writing were muchbetter, because of reduced oscillopsia: the image of the visualsurrounding was stable. The patient was able to suppress the nystagmusby visual fixation. In addition, the patient's spatial orientation wasimproved.

Clinical examination by two independent examiners revealed a reductionof the nystagmus and video-oculography showed that the patient couldsuppress the nystagmus by visual fixation. The patient's visual acuitywas: right 0.83, left 1.0, binocular 1.

Posturography demonstrated a reduction of postural sway.

Overall, this case study demonstrates improvement in the patient'ssymptoms for this indication.

Patient 2

The patient in this case study was diagnosed with downbeat nystagmus.The patient showed postural imbalance and dizziness. The patient did notbenefit from Fampyra®.

The patient began taking acetyl-DL-leucine (3 g/day for the first week;5 g/day thereafter) and subsequently showed improvement of gait, withthe ability to walk much longer distances (one hour), and improvedalertness. The patient's downbeat nystagmus also improved (documented byvideo-oculography). The patient could partially suppress the nystagmusby visual fixation, as evaluated using a target center (dot presented inthe center of a display for 30 seconds, FIG. 13A) and in completedarkness using goggles covered with special glasses for 45 seconds (FIG.13B). The results (median of slow phase velocity, SPV) were as follows:Target Center—horizontal: −0.02°/s, vertical: 2.41°/s; CompleteDarkness—horizontal: 0.05°/s, vertical: 3.27°/s (FIG. 13C). The patientwas able to minimize eye movements while fixating, as shown in FIG. 13A.

Gait analysis showed an increase of self-chosen velocity from 56 to 85cm/sec and maximal gait velocity from 122 to 155 cm/sec. Medication wasthen suspended.

About one month after stopping acetyl-DL-leucine treatment, thepatient's symptomatology worsened. Gait analysis showed a decrease ofself-chosen velocity from 85 to 72 cm/sec and maximal gait velocity from155 to 113 cm/sec.

Example 13

Patient 1

The patient in this case study was a 70 year-old female with mainlyright sided hypokinetic-rigid syndrome and tremor, antecollis, frequentfalls, orthostatic dysfunction and urge incontinence.

The patient was diagnosed with multiple system atrophy Parkinson type(MSA-P). Datscan revealed a mainly left sided reduction ofdopamine-receptors and FDG-PET of the brain showed a mainlyparieto-occipital reduced metabolism. There was a discreet Levodoparesponse (100/25 mg 3× daily).

The patient began taking acetyl-DL-leucine (3 g/day for the first week;5 g/day thereafter). After 3 weeks on acetyl-DL-leucine, the patient wasevaluated and reported no significant improvement of gait, reduction offalls or improved hypokinetic rigid-syndrome. Medication was stopped.

6 weeks later the patient did not report deterioration of symptoms afterstopping medication.

Patient 2

The patient in this case study was a 78 year-old male diagnosed withmultiple system atrophy Parkinson type (MSA-P). The patient'ssymptomatology was characterized by a progressive hypokinetic-rigidsyndrome, orthostatic dysfunction and consecutive dizziness and balancedisorder. The patient showed saccadic eye movement and symmetric rigorof both upper limbs. Balancing on an imaginary tightrope was associatedwith insecureness and loss of balance. FDG-PET of the brain showed areduced metabolism of both parietal and occipital cortex, suggestive forLewy-Body-Dementia.

The patient was started on treatment with acetyl-DL-leucine, at a doseof 3 g per day for the first week, then 5 g per day. The patient wasexamined before initiation of treatment and showed the clinicalsymptomatology described above, with very pronounced insecure gait anddizziness.

After one month of treatment, medication was stopped and the patient wasevaluated. The patient reported subjective improvement of dizziness andclinical examination showed improved balancing on an imaginarytightrope, which the patient performed without any difficulties comparedto the prior examination. Gait analysis was performed.

After one month without medication, the patient reported stablesymptomatology. No worsening of dizziness or insecurity of gait wasreported. Gait analysis was performed.

After two months without medication, a gait analysis was performed andshowed reduction of velocity of gait, reduction of step length andworsening of FGA-Score. The patient reported a worsening of generalsymptomatology, including progressive weakness of legs and increasedinsecureness of gait.

TABLE 11 Gait analysis parameters. After 1 After 1 After 2 month monthmonths of without without Normal values treatment treatment treatment(±SD) speed (cm/sec) 109 114 94 110.81 (18.33) Max. speed (cm/sec) 214196 177 158.30 (22.66) cadence (steps/ 109 109 106 109.19 (12.75)minute) Track width (cm) 3.8 2.3 3.4  9.06 (1.94) Step cycle length 120126 107 121.81 (11.52) (cm) Double stance (%) 25.6 22.5 26.7  20.73(2.55) Coefficient of 2.7 1.7 2.1  1.94 (0.85) variation (temporal)Functional Gait 24/30 25/30 22/30  24.9 (3.6) Assessment

Patient 3

The patient in this case study was a 78 year-old male diagnosed withmultiple system atrophy Parkinson type (MSA-P). The patient'ssymptomatology was characterized by progressive hypokinetic-rigidsyndrome, urinary incontinence, incipient cognitive dysfunction, andgait disorder with small steps and 2-3 falls per month. Cognitivedeficits were characterized by psychomotoric slowing and intermittentmental confusion. Datscan revealed a reduction of dopamine-receptors,which supported the diagnosis. FDG-PET of the brain showed a mainlystriatal reduced metabolism. Levodopa therapy was suspended due to sideeffects.

The patient was started on treatment with acetyl-DL-leucine, at a doseof 3 g per day for the first week, then 5 g per day. The patientevaluated after one month on acetyl-DL-leucine. The patient's wifereported a significant improvement of cognitive function. Episodes ofmental confusion completely disappeared. The patient's cognitivestructure seemed much clearer and straighter. There was no improvementof gait function. The patient's wife supported continuing themedication.

Example 14

The patient in this case study was a 45-year-old male diagnosed withspinocerebellar ataxia 28 (SCA 28). Genetic testing showed a knownpathogenic variant in AFG3L2. The patient's symptomatology wascharacterized by progressive cerebellar syndrome since the age of 30,characterized by slurred speech, unstable gait, balance disorder anddizziness. The patient's father and grandmother suffered from a similarsymptomatology. The patient showed saccadic eye movements and dysmetriain the coordination tests, ataxic gait, slurred speech, exaggeratedreflexes of the lower limbs, spasticity of the lower limbs and apositive Babinski sign on the left. cMRI showed a marked atrophy of thecerebellum.

The patient was started on treatment with acetyl-DL-leucine at a dose of5 g per day. A gait analysis was performed before treatment commenced.After about one month of treatment, medication was stopped and thepatient was evaluated. The patient reported an improvement of thesymptomatology, in particular reduced dizziness (almost vanished), and amore stable gait. The patient reported that he no longer walked like arobot and could climb the stairs without using the banisters. A gaitanalysis was performed, which showed an improvement of parameters.

TABLE 12 Gait analysis parameters. After treatment Before for oneStandard values treatment month (±SD) Self-chosen speed 101 118 126.61(21.43) (cm/sec) Maximum speed 188 201 182.94 (25.37) (cm/sec) Cadence100 105 115.52 (9.36) (steps/minute) Track width (cm) 14.5 11.7  9.43(2.27) Step cycle length (cm) 122 135 131.55 (17.98) Double stance (%)24.9 23.8  18.76 (3.46) Coefficient of variation 4.1 2.1  1.88 (0.79)(temporal) Functional Gait Assessment 24/30 23/30  28.9 (1.5)

Example 15

Patients 1 & 2

The patients in this case study were 2 female siblings, 24 (Patient 1)and 19 (Patient 2) years old, respectively. The patients suffer fromataxia telangiectasia.

Patient 1 showed delayed developmental milestones. The patient did notwalk until 2 years of age and had progression of cerebellar ataxia signsand symptoms, seizures, together with generalized, distal pronouncedhypertonia and telangiectasias on the eyes, ears, and chest. Diagnosiswas established at the age of 9 years. Patient 1's ocular motor functionshowed downbeat-nystagmus with gaze straight-ahead and in the gaze tothe left greater than right, gaze-holding nystagmus upward, vertical andhorizontal saccadic smooth pursuit, and hypometric saccades horizontallyand vertically, with restricted motility upward.

Before treatment was commenced, examination of Patient 1 indicated aScale for Assessment and Rating of Ataxia (SARA) score of 22/40. Resultsfrom the patient's Spinocerebellar Ataxia Functional Index (SCAFI)analysis were:

-   -   Mean 8-meters Walking Test (8MW): 21.8 s    -   MW 9-Hole Pegboard Test Dominant (9HPTD) (right): 90.2 s    -   MW 9-Hole Pegboard Test Non-Dominant (9HPTND): 125.8 s    -   MW PATA Word Test: 12.5    -   Visual analog scale (as evaluated by the patient): 99

Results from video-oculography were:

TABLE 13 Video-oculography parameters. Slow phase velocity of the gaze-holding nystagmus Horizontal Vertical Centrum 0.54 6.9 Vpravo −1.16 6.2Vl′avo 12.2 12.6 Nadol −0.14 6.9 Nahor −0.39 5.95

Patient 1 began treatment with acetyl-DL-leucine (5 g/day) followingexamination. After one month of treatment, the patient was re-evaluated.Caregivers reported an improvement of speech and gait. The patientherself did not perceive any change. Examination indicated a Scale forAssessment and Rating of Ataxia (SARA) score of 15.5/40. Results fromthe patient's Spinocerebellar Ataxia Functional Index (SCAFI) analysiswere:

-   -   Mean 8-meters Walking Test (8MW): 18.5 s    -   MW 9-Hole Pegboard Test Dominant (9HPTD) (right): 77.9 s    -   MW 9-Hole Pegboard Test Non-Dominant (9HPTND): 101.3 s    -   MW PATA Word Test: 13    -   Visual analog scale (as evaluated by the patient): 85

Results from video-oculography were:

TABLE 14 Video-oculography parameters. Slow phase velocity of thegaze-holding nystagmus Horizontal Vertical Center 0.4 4.77 Right −0.954.83 Left 8.2 8.85 Down −0.44 5.29 Up 0.72 2.67

Patient 1's SARA and SCAFI subsets improved after treatment, andvideo-oculography showed significant improvement of fixation stabilityand decrease of intensity of downbeat-nystagmus.

Patient 2 showed delayed developmental milestones, seizure at the age of1, generalized hypotonia, contractures of low extremities with pesequinovarus bilaterally, areflexia, acute lymphoblastic leukemia at theage of 3 years, slightly enlarged spleen, hypercholesterolemia,hypochromatic microcytic anemia, pigmental naevi, and vitiligo. Firstsymptoms were noticed by the patient's parents at the age of 15 months.Patient 2's ocular motor function showed square wave jerks, gaze-holdingnystagmus left greater than right with vertical component,downbeat-nystagmus, saccadic smooth pursuit, vertical gaze palsy upwardgreater than downward, and impaired convergence.

Before treatment was commenced, examination of Patient 2 indicated aScale for Assessment and Rating of Ataxia (SARA) score of 28.5/40.Results from the patient's Spinocerebellar Ataxia Functional Index(SCAFI) analysis were:

-   -   Mean 8-meters Walking Test (8MW): not able to perform without        support    -   MW 9-Hole Pegboard Test Dominant (9HPTD) (right): 300 s    -   MW 9-Hole Pegboard Test Non-Dominant (9HPTND): 299.2 s    -   MW PATA Word Test: 13.5    -   Visual analog scale (as evaluated by the patient): 45

Results from video-oculography were:

TABLE 15 Video-oculography parameters. Slow phase velocity of thegaze-holding nystagmus Horizontal Vertical Center −2 6.18 Right −3.977.6 Left −0.24 9.49 Down −2.86 5.58 Up −1.11 4.97

Patient 2 began treatment with acetyl-DL-leucine (5 g/day) followingexamination. After one month of treatment, the patient was re-evaluated.Caregivers reported an improvement of fine motor function, hand tremor,and speech. The patient herself did not perceive any benefit.Examination indicated a Scale for Assessment and Rating of Ataxia (SARA)score of 23.5/40. Results from the patient's Spinocerebellar AtaxiaFunctional Index (SCAFI) analysis were:

-   -   Mean 8-meters Walking Test (8MW): not able to perform without        support    -   MW 9-Hole Pegboard Test Dominant (9HPTD) (right): 300 s    -   MW 9-Hole Pegboard Test Non-Dominant (9HPTND): 300 s    -   MW PATA Word Test: 14    -   Visual analog scale (as evaluated by the patient): 80    -   Results from video-oculography were:

TABLE 16 Video-oculography parameters. Slow phase velocity of thegaze-holding nystagmus Horizontal Vertical Center −1.45 5.6 Right −3.456.56 Left 3.58 7 Down −2.5 4.69 Up −0.51 3.15

Video-oculography showed improvement of fixation stability andsignificant improvement of downbeat-nystagmus intensity in Patient 2.

Patient 3

The patient in this case study was a 19 year old female suffering fromataxia telangiectasia from early childhood, having:

-   -   Delayed motor development, cerebellar ataxia signs and symptoms,        pronounced axial hypotonia with acral hypertonia, severe        contractures of feet with orthopedic deformities pes equinus et        transversoplanus bilaterally and was thus confined to        wheelchair, dysdiadochokinesis, and areflexia of low extremities        with decreased proprioceptive perception; and    -   Non-Hodgkin lymphoma, polymorphism MTHFR (C677T), lymphangioma        of the lower lip, cholecystolithiasis, dilated cardiomyopathy,        pigmental naevi, thoraco-lumbar kyphoscoliosis, and scleral        teleangiectasias on both eyes.

The patient's ocular motor function showed gaze-holding nystagmus to theright and to the left, saccadic eye movements, slow saccades to alldirections, especially horizontally, pathological vestibulo-ocularreflex with corrective catch-up saccades, and pathologicalvisual-fixation suppression of the vestibulo-ocular reflex.

Before treatment was commenced, examination of the patient indicated aScale for Assessment and Rating of Ataxia (SARA) score of 23/40. Resultsfrom the patient's Spinocerebellar Ataxia Functional Index (SCAFI)analysis were:

-   -   Mean 8-meters Walking Test (8MW): not able to perform    -   MW 9-Hole Pegboard Test Dominant (9HPTD) (right): 150 s    -   MW 9-Hole Pegboard Test Non-Dominant (9HPTND): 161.6 s    -   MW PATA Word Test: 14    -   Visual analog scale (as evaluated by the patient): 80

Results from video-oculography were:

TABLE 17 Video-oculography parameters. Slow phase velocity of thegaze-holding nystagmus [°/s] Horizontal Vertical Center 3 −1.5 Right−0.4 −1 Left 7.3 2.5 Down 2.4 −0.2

The patient began treatment with acetyl-DL-leucine (5 g/day) about sixmonths after the examination. After slightly over 7 months of treatment,the patient was re-evaluated. Caregivers and patient reported generalimprovement of well-being, without clearer specification. Examinationindicated a Scale for Assessment and Rating of Ataxia (SARA) score of21.5/40. Results from the patient's Spinocerebellar Ataxia FunctionalIndex (SCAFI) analysis were:

-   -   Mean 8-meters Walking Test (8MW): not able to perform    -   MW 9-Hole Pegboard Test Dominant (9HPTD) (right): 124.5s    -   MW 9-Hole Pegboard Test Non-Dominant (9HPTND): 147.5 s    -   MW PATA Word Test: 10    -   Visual analog scale (as evaluated by the patient): 80

Results from video-oculography were:

TABLE 18 Video-oculography parameters. Slow phase velocity of the gaze-holding nystagmus [°/s] Horizontal Vertical Center −0.1 0.4 Right −4.21.7 Left 1.7 0.1 Down −0.6 1.2

The patient showed slight improvement of SARA and SCAFI subset 9HPT, andsignificant improvement of fixation stability and decrease of intensityof gaze-holding nystagmus at all positions.

Patient 4

The patient in this case study was a 15 year-old female suffering fromataxia telangiectasia from 4-years of age. From 7-years of age, thepatient showed severe cerebellar ataxia signs and symptoms, fine motorimpairment, muscular hypotonia with areflexia, muscular atrophy, andplantar flexion with discrete contractures. The patient was confined toa wheelchair, but was able to walk with constant support. The patienthad severe hemolytic anemia, hypogammaglobulinemia, telangiectasias onthe scleras and chest, Secondary Cushing syndrome due to corticosteroidintake, and was suspected of having CNS Non-Hodgkin lymphoma.

The patient's ocular motor function showed slow deviation of the eyesupward, left beating nystagmus in the central position, gaze-holdingnystagmus in all directions, horizontally with downbeating component,startle with sudden head movement.

Before treatment was commenced, examination of the patient indicated aScale for Assessment and Rating of Ataxia (SARA) score of 23.5/40.Results from the patient's Spinocerebellar Ataxia Functional Index(SCAFI) analysis were:

-   -   Mean 8-meters Walking Test (8MW): not able to perform    -   MW 9-Hole Pegboard Test Dominant (9HPTD) (right): 124.5 s    -   MW 9-Hole Pegboard Test Non-Dominant (9HPTND): 52.3 s    -   MW PATA Word Test: 14    -   Visual analog scale (as evaluated by the patient): 70

Results from video-oculography were:

TABLE 19 Video-oculography parameters. Slow phase velocity of the gaze-holding nystagmus [°/s] Horizontal Vertical Center −0.6 1.76 Right 3.7−0.1 Left −6 0.6 Down 5.7 2.7

The patient began treatment with acetyl-DL-leucine (5 g/day) followingthe examination. After slightly over 1 month of treatment, the patientwas re-evaluated. The patient and her mother reported improvement inhandwriting, especially due to decreased hand tremor and fine motorfunction. The patient also reported that drinking was easier and nolonger needed a straw. Family members described improvement of gait,with increased stability and needing less support. Examination indicateda Scale for Assessment and Rating of Ataxia (SARA) score of 18.5/40.Results from the patient's Spinocerebellar Ataxia Functional Index(SCAFI) analysis were:

-   -   Mean 8-meters Walking Test (8MW): not able to perform    -   MW 9-Hole Pegboard Test Dominant (9HPTD) (right): 93.5 s    -   MW 9-Hole Pegboard Test Non-Dominant (9HPTND): 101.7 s    -   MW PATA Word Test: 15.5    -   Visual analog scale (as evaluated by the patient): 70

Results from video-oculography were:

TABLE 20 Video-oculography parameters. Slow phase velocity of the gaze-holding nystagmus [°/s] Horizontal Vertical Center −0.2 4.8 Right −1 0.3Left −0.8 1.9 Down −0.7 −2.3

The patient showed improvement of SARA and SCAFI subset 9HPT of thedominant hand. Video-oculography showed general improvement of fixationstability and decrease of intensity of spontaneous and gaze-holdingnystagmus at all positions.

Patient 5

The patient in this case study was a 10 year-old boy suffering fromataxia telangiectasia from his early childhood, having:

-   -   Delayed psychomotor development, instable walking at 14 months        with increased incidence of falls, severe cerebellar ataxia        signs and symptoms, dysarthria and dyslalia, fine motor        impairment, infrequent head tremor, slow psychomotor tempo,        hypotonia with muscular atrophy and hyporeflexia, anteflexia of        the head with kyphosis in the thoracal area, pedes        transversoplani, scapullae allatae, parasomnia with pavor        nocturnus, and autism; and    -   Significant immunosuppression, telangiectasias on the soft        palate, scleras, incontinence, and asthenic habitus.

The patient was confined to a wheelchair but was able to perform a fewsteps with strong constant support. The patient's ocular motor functionshowed oculomotor apraxia with pronounced head anteflexia, head and eyemovement “en bloc” when looking to the right and left, vertical gazepalsy with slow vertical saccades and saccadic smooth pursuit, slowhorizontal saccades to the left, saccade palsy to the right, restrictedeye motility, especially vertically, and fixation instability in allpositions.

Before treatment was commenced, examination of the patient indicated aScale for Assessment and Rating of Ataxia (SARA) score of 24.5/40.Results from the patient's Spinocerebellar Ataxia Functional Index(SCAFI) analysis were:

-   -   Mean 8-meters Walking Test (8MW): not able to walk without        constant support    -   MW 9-Hole Pegboard Test Dominant (9HPTD) (right): 102.7 s    -   MW 9-Hole Pegboard Test Non-Dominant (9HPTND): 116.8 s    -   MW PATA Word Test: 6    -   Visual analog scale (as evaluated by the patient): 90

Results from video-oculography were:

TABLE 21 Video-oculography parameters. Slow-phase velocity (SPV) offixation and gaze-holding nystagmus, [°/s] Horizontal Vertical Center0.96 1.53 Right 0.21 2 Left 2.1 3.64 Down 0.71 3.91 Up 0.31 1.69

The patient began treatment with acetyl-DL-leucine (5 g/day) followingexamination. After about 1 month of treatment, the patient wasre-evaluated. The patient's mother described a significant improvementof stability of the gait; prior to the therapy, he was constantlyfalling backward and had to be partially “transported”. On medication,he was able to walk with only holding the caregiver's hand.

Fine motor function, the intensity of hand tremor, and body holdingimproved. Improvement of fine motor function was reflected in dailyactivities, such as eating and drinking independently. The patientgained 1.5 kg and had a better appetite. Examination indicated a Scalefor Assessment and Rating of Ataxia (SARA) score of 20.5/40. Resultsfrom the patient's Spinocerebellar Ataxia Functional Index (SCAFI)analysis were:

-   -   Mean 8-meters Walking Test (8MW): not able to walk without        support    -   MW 9-Hole Pegboard Test Dominant (9HPTD) (right): 103.6 s    -   MW 9-Hole Pegboard Test Non-Dominant (9HPTND): 88.8 s    -   MW PATA Word Test: 7.5    -   Visual analog scale (as evaluated by the patient): 80

Results from video-oculography were:

TABLE 22 Video-oculography parameters. Slow-phase velocity (SPV) offixation and gaze-holding nystagmus, [°/s] Horizontal Vertical Center0.79 3.54 Right 1.17 2.36 Left 1.22 2.53 Down 0.62 1.08 Up 0.33 1.71

After almost 7 months of treatment, the patient was again re-evaluated.The patient's mother described significantly more stable gait; thisfinding remained constant from the first evaluation after treatment. Thepatient had improved concentration and speech. The patient could standup on his own and was generally more independent with daily activities.The patient gained another 3 kg with improved appetite and showedimproved strength.

Examination indicated a Scale for Assessment and Rating of Ataxia (SARA)score of 17.5/40. Results from the patient's Spinocerebellar AtaxiaFunctional Index (SCAFI) analysis were:

-   -   Mean 8-meters Walking Test (8MW): 15.3 s (holding of the hand)    -   MW 9-Hole Pegboard Test Dominant (9HPTD) (right): 92.4 s    -   MW 9-Hole Pegboard Test Non-Dominant (9HPTND): 98.3 s    -   MW PATA Word Test: 11    -   Visual analog scale (as evaluated by the patient): 100

The patient was re-evaluated after slightly over a year of treatment andshowed improved social interaction, activity, and agility. The patient'sparents reported improvement of incontinence. The patient developed arepeatedly occuring frontal localized pain with vomiting in the morning.Based on family history, it was suspected that the localized pain may bedue to infantile migraine.

Examination indicated a Scale for Assessment and Rating of Ataxia (SARA)score of 16.5/40. Results from the patient's Spinocerebellar AtaxiaFunctional Index (SCAFI) analysis were:

-   -   Mean 8-meters Walking Test (8MW): 13.9 s (able to walk by        himself, mother held hand)    -   MW 9-Hole Pegboard Test Dominant (9HPTD) (right): 95.6 s    -   MW 9-Hole Pegboard Test Non-Dominant (9HPTND): 127.6 s    -   MW PATA Word Test: ¹4.5    -   Visual analog scale (as evaluated by the patient): 95

On treatment with acetyl-DL-leucine, the patient showed improved SARAand SCAFI subtests, increased quality of life, generally improvedfixation stability and decrease of intensity of spontaneous andgaze-holding nystagmus, especially in the vertical plane (after 1month).

Patient 6

The patient in this case study was a 10 year-old female suffering fromataxia telangiectasia who had ataxic gait and stance, fine motorfunction disorder with hand tremor, dysphagia and speech disorder,ocular movement disorder, and problems with cognitive function andconcentration. First symptoms were observed at the age of one year.

After baseline examination, the patient started acetyl-DL-leucinetreatment at 1.5 g/day for the first week and at 3 g/day for the secondweek onwards. The patient was evaluated after one month and six monthsof treatment, respectively. After one month of treatment, the patientshowed increased fine motor skills with reduced hand tremor, improvedpostural stability and gait, increased enunciation, and increasedself-confidence. After six months of treatment, the patient had stablegeneral conditions, stable gait and stance, and improved handwriting.The patient, however, was suffering from anxiety, which would beexpected to negatively influence the response.

The patient's SARA and SCAFI scores at each evaluation are shown below.

TABLE 23 Patient Evaluation parameters. After one month After six monthsof acetyl- of acetyl- Baseline DL-leucine treatment DL-leucine treatmentSARA 11/40 8.5/40 11/40 8MWT  8.95 sec  8.45 sec  7.53 sec 9HPTD 85.38sec 81.95 sec 136.27 sec 9HPTND  71.2 sec 70.39 sec  80.32 sec PATA 14.515.5 13

Example 16

The patient in this case study was a female in her early 60s who wasgenetically diagnosed with Spinocerebellar Ataxia (SCA) 1. Beforetreatment, the patient had severe problems with speaking and swallowing,tremor of both arms, spasticity and moderate ataxia of stance and gait.The patient also had problems sleeping.

Three weeks on medication with acetyl-DL-leucine (5 g/day), all symptomssignificantly improved, as further demonstrated by clinical examination,including spasticity and impairment of ocular motor function.

Three months later the medication was stopped. After two weeks, theintensity of the signs and symptoms were the same as before therapy.Treatment was started again, and the patient has remained, andcontinues, on the treatment after over two years, on the same dosagewithout any side-effects.

The patient's daughter reported considerable progression of the diseaseover time with a persisting symptomatic effect, yet observed,anecdotally, that there was long-term symptomatic efficacy fromtreatment.

Example 17

The patient in this case study was a 70 year-old female with insecuregait and frequent falls, visual hallucinations at night, REM-sleepdisorder. The patient had symmetric hypokinetic-rigid syndrome withimpairment of fine motor skills and fluctuations in attention andawareness.

The patient was diagnosed with Lewy Body dementia. FDG-PET of the brainshowed a synaptic dysfunction in the parietal and occipital lobe andDATscan showed a degeneration of presynaptic dopamine transporter,supporting the diagnosis. Treatment with Levodopa 100 mg 4× daily andQuetiapin 25 mg at night improved the symptomatology.

The patient started taking acetyl-leucine (3 g/day for one week; 5 g/daythereafter) and was evaluated after four weeks. The patient reportedincreased fatigue and a deterioration of balance and speech. Medicationwas reduced to 3 g/day, and the patient was instructed to stopmedication about two weeks later.

The patient was re-evaluated about one month after ceasing medicationand did not report improvement of symptomatology with the decreased doseand no deterioration of symptoms after stopping medication.

TABLE 24 Gait parameters. After After 1 week 4 weeks Normal on acetyl-on acetyl- value DL-leucine DL-leucine (±SD) speed (cm/sec) 55 56 119.12(17.27) Max. speed (cm/sec) 92 74 176.78 (19.10) cadence (steps/minute)81 85 113.06 (10.38) Track width (cm) 4.6 6.7  9.49 (3.56) Step cyclelength (cm) 81 79 126.71 (13.06) Double stance (%) 36.1 38.7  20.35(3.21) Coefficient of variation 9.1 8.8  1.76 (0.73) (temporal)Functional Gait Assessment 11/30  27.1 (2.3)

Example 18

In this case study, four patients (male siblings) suffered from, andwere later diagnosed with, ataxia with oculomotor apraxia type 4. Theolder three siblings were 12, 11, and 10 years of age, respectively, atthe time of disease onset. Prior to commencing treatment withacetyl-DL-leucine, by the age of 15/16 years, the three older siblingswalked with an expedient, as reported by the patients' mother. The oldersiblings began treatment with acetyl-leucine at 25, 23, and 19 years ofage, respectively, and have been on the treatment for approximately fouryears. No long-term clinical data is available for these three patients.

The youngest sibling was 11 years old at the time of onset. He begantreatment with acetyl-DL-leucine at the age of 13. While on treatment,the youngest sibling did not walk with an expedient until nearly 18years of age, as reported by the patient's mother. The patient's motheralso reported that the youngest sibling had improved fine motor skillsand improved speech at each age compared to his older siblings. Nolong-term clinical data is available for the youngest sibling.

Example 19

An NPC patient's severity may be quantified by assigning a clinicalseverity score (CSS), which assesses various parameters of the diseaseand gives each parameter a score out of 5 (higher score=greaterseverity). See Yanjanin et al., “Linear Clinical Progression,Independent of Age of Onset, in Niemann-Pick Disease, Type C,” Am J MedGenet Part B 153B:132-140. In an untreated patient, one can typicallypredict how the CSS will change over time in an individual, as diseaseprogression appears to be linear. For example, if Patient A moves from aCSS of 8 to a CSS of 12 between month o and month 12, it can bepredicted that by month 36, the patient will have a CSS of 20. Theannual severity increment score (ASIS) quantities the annual rate ofchange in the CSS, calculated by dividing the CSS of a patient by thepatient's age. For example, if untreated Patient B had a CSS of 8 at twoyears of age, the patient's ASIS would be 4. Each year, the patientwould be expected to progress by 4 CSS points, such that at 4 years ofage, the patient's CSS would be 16. If therapeutic intervention slowedor arrested disease progression, one would expect the patient to have asmaller ASIS score after such therapy than at baseline.

Ten NPC patients were administered acetyl-leucine at 4.5 g/day over longdurations. A CSS was determined at baseline, and at various time points,for eye movement, ambulation, speech, swallow, fine motor skills,cognition, memory, and seizures. An overall CSS was calculated atbaseline and at each such time point by adding the individual CSS valuesfor each parameter (eye movement, ambulation, etc.). The number of dayspost-initiation of therapy at which CSS was assessed was different foreach patient, as shown in Table 25.

TABLE 25 Days post-initiation of acetyl-leucine administration at whichCSS was assessed Patient Baseline Time Point Time Point Time Point I.D(days) 2 (days) 3 (days) 4 (days) 1 0 126 231 2 0 119 200 297 3 0 91 2404 0 107 196 5 0 78 238 414 6 0 184 238 414 7 0 81 165 8 0 90 217 9 0 400644 10  0 83

Tables 26-34 below show each CSS for overall, eye movement, ambulation,speech, swallow, fine motor skills, cognition, memory, and seizures,respectively.

TABLE 26 CSS overall. Clinical Severity Score (CSS) Time Point TimePoint Time Point Patient I.D Baseline 2 3 4 1 11 11 10 2 33 33 33 33 313 12 11 4 13 13 10 5 12 12 12 12 6 21 23 21 21 7 19 19 19 8 13 12 11 922 22 21 10  14 11

TABLE 27 CSS eye movement. Clinical Severity Score (CSS) Time Point TimePoint Time Point Patient I.D Baseline 2 3 4 1 3 3 3 2 3 3 3 3 3 3 3 3 42 2 2 5 3 3 3 3 6 3 3 3 3 7 3 3 3 8 3 3 2 9 3 3 3 10  3 3

TABLE 28 CSS ambulation. Clinical Severity Score (CSS) Time Point TimePoint Time Point Patient I.D Baseline 2 3 4 1 2 2 1 2 5 5 5 5 3 1 1 1 42 2 1 5 1 1 1 1 6 2 4 2 2 7 2 2 2 8 1 1 1 9 2 2 2 10  2 2

TABLE 29 CSS speech. Clinical Severity Score (CSS) Time Point Time PointTime Point Patient I.D Baseline 2 3 4 1 1 1 1 2 2 2 2 2 3 1 1 1 4 2 2 15 1 1 1 1 6 2 2 2 2 7 1 1 1 8 1 1 1 9 2 2 2 10  1 1

TABLE 30 CSS swallow. Clinical Severity Score (CSS) Patient I.D BaselineTime Point 2 Time Point 3 Time Point 4 1 0 0 0 2 4 4 4 4 3 2 2 2 4 2 2 25 2 2 2 2 6 3 3 3 3 7 3 3 3 8 2 2 2 9 3 3 3 10 2 2

TABLE 31 CSS fine motor skills. Clinical Severity Score (CSS) PatientI.D Baseline Time Point 2 Time Point 3 Time Point 4 1 1 1 1 2 5 5 5 5 32 1 1 4 1 1 1 5 1 1 1 1 6 4 4 4 4 7 2 2 2 8 2 1 1 9 4 4 4 10 1 1

TABLE 32 CSS cognition. Clinical Severity Score (CSS) Patient I.DBaseline Time Point 2 Time Point 3 Time Point 4 1 3 3 3 2 5 5 5 5 3 3 33 4 3 3 3 5 3 3 3 3 6 4 4 4 4 7 4 4 4 8 3 3 3 9 4 4 4 10 3 2

TABLE 33 CSS memory. Clinical Severity Score (CSS) Patient I.D BaselineTime Point 2 Time Point 3 Time Point 4 1 1 1 1 2 4 4 4 4 3 1 1 0 4 1 1 05 1 1 1 1 6 3 3 3 3 7 4 4 4 8 1 1 1 9 4 4 3 10 2 0

TABLE 34 CSS seizures. Clinical Severity Score (CSS) Patient I.DBaseline Time Point 2 Time Point 3 Time Point 4 1 0 0 0 2 5 5 5 5 3 0 00 4 0 0 0 5 0 0 0 0 6 0 0 0 0 7 0 0 0 8 0 0 0 9 0 0 0 10 0 0

The ASIS at baseline and each time point was calculated using eachpatient's CSS and age at the time of assessment. The overall ASIS foreach patient at each time point is shown below in Table 35.

TABLE 35 ASIS overall. Annual Severity Increment Scores (ASIS) BaselineTime Point 2 Time Point 3 Time Point 4 0.381371618 0.3768642720.339262493 1.94125463 1.904748736 1.880675612 1.852636028 0.650.592617631 0.53250497  0.481909063 0.476731928 0.363469002 0.4331883770.429874461 0.423232908 0.416160273 0.561964246 0.607297766 0.5523331170.545420607 0.536675431 0.533334614 0.529913714 0.486750384 0.4452006090.402903129 0.738624874 0.71243018  0.665646967 0.595597228 0.406038403

As shown in Table 26 and FIG. 10A, none of the ten patients showed anoverall increase in CSS over the course of the experiment. Patient 6showed an increased CSS between baseline and time point 2, but returnedto baseline by time point 3 and remained there at time point 4. Four ofthe ten patients (Patients 2, 5, 6, and 7) had a constant CSS over thecourse of the experiment, indicating that the disease did not progressin these individuals. Six of the ten patients (Patients 1, 3, 4, 8, 9,and 10) showed a reduction in CSS over the course of the experiment,indicating that the disease did not progress and actually became lesssevere. Improvements were seen in different subscores: Patient 1:ambulation; Patient 3: fine motor skills; Patient 4: ambulation andspeech; Patient 8: eye movement and fine motor skills; Patient 9:memory; Patient 10: cognition. Data presented in FIGS. 11A-11J show theCSS subscores for each patient, respectively, in the form of a bargraph.

As shown in Table 35 and FIGS. 10B, all ten patients showed a reductionin ASIS during treatment relative to ASIS at baseline. In Patients 2, 5,6, and 7, CSS remained the same while age increased, resulting in asmall reduction in ASIS. In Patients 1, 3, 4, 8, 9, and 10, thereduction in ASIS was larger due to CSS decreasing while age increased.

Example 20

The Niemann-Pick Disease Type C (NPC) mouse model shares a number ofpathological features with Alzheimer's disease (AD) as described herein.Wild type NPC1^(−/−) mice were treated with acetyl-dl-leucine (0.1 g/kgbody weight daily) from 3 weeks of age. Mice were sacrificed at 8 weeksof age. Levels of amyloid precursor protein C-terminal fragments(APP-CTFs) were evaluated relative to total amyloid precursor protein(APP) levels in the cerebellum for wild type, untreated wild typeNPC1^(−/−) mice, and AL-treated wild type NPC1^(−/−) mice. Levels ofmicrotubule-associated protein 1A/1B-light chain3-phosphatidylethanolamine conjugate (LC3-II) were also evaluatedrelative to levels of tubulin loading control for wild type, untreatedwild type NPC1^(−/−) mice, and AL-treated wild type NPC1^(−/−) mice.

The APP-CTF data is shown in FIG. 12A. The data replicated thepreviously noted accumulation of APP-CTFs in the NPC1 mouse brain.Treatment with acetyl-dl-leucine was associated with lowering ofAPP-CTFs.

The LC3-II data is shown in FIG. 12B. The data replicated the previouslynoted accumulation of LC3-II in the NPC1 mouse brain. Treatment withacetyl-dl-leucine was associated with a lowering of LC3-II, indicativeof a partial restoration of autophagic flux.

Conclusion

Acetyl-leucine treatment was associated with an improvement in ADpathology in the NPC1 mouse brain.

1-29. (canceled)
 30. A method of treating a neurodegenerative disease orone or more symptoms associated with a neurodegenerative disease in asubject in need thereof comprising: administering a therapeuticallyeffective amount of acetyl-leucine or a pharmaceutically acceptable saltthereof to the subject, wherein the neurodegenerative disease is notcerebellar ataxia or Niemann-Pick type C disease.
 31. The methodaccording to claim 30, wherein the neurodegenerative disease isassociated with lysosomal dysfunction.
 32. The method according to claim31, wherein the neurodegenerative disease associated with lysosomaldysfunction is chosen from alcoholism, Alzheimer's disease, amyotrophiclateral sclerosis (ALS), Canavan disease, frontotemporal lobardegeneration, Huntington's disease, multiple system atrophy(MSA-P/MSA-C), multiple sclerosis, narcolepsy, Parkinson's Disease,Smith Lemli Opitz Syndrome (SLOS) (an inborn error of cholesterolsynthesis), Tangier disease, Pelizaeus-Merzbacher Disease, Pick'sdisease, frontotemporal dementia with parkinsonism, prion diseases,progressive supranuclear palsy, spinal muscular atrophy, andneurodegenerative lysosomal storage disorders (LSDs).
 33. The methodaccording to claim 32, wherein the neurodegenerative disease associatedwith lysosomal dysfunction is chosen from ALS, MSA-P, MSA-C,frontotemporal dementia with parkinsonism, progressive supranuclearpalsy, and Alzheimer's disease.
 34. The method according to claim 30,wherein the neurodegenerative disease is chosen from Alexander'sdisease, Alper's disease, cerebral palsy, Cockayne syndrome,corticobasal degeneration, HIV-associated dementia, Kennedy's disease,neuroborreliosis, primary lateral sclerosis, Refsum's disease,Schilder's disease, subacute combined degeneration of spinal cordsecondary to pernicious anaemia, hereditary motor and sensory neuropathywith proximal dominance, Wobbly Hedgehog Syndrome (WHS), progressivemuscular atrophy (Duchenne-Aran muscular atrophy), progressive bulbarpalsy, pseudobulbar palsy, HIV-associated neurocognitive disorders(HAND), Vascular Parkinsonism, lower body Parkinson's syndrome, andcerebellar downbeat nystagmus.
 35. The method according to claim 30,wherein the neurodegenerative disease is a Motor Neuron Disease.
 36. Amethod of treating treating a neurodegenerative disease or one or moresymptoms associated with a neurodegenerative disease in a subject inneed thereof comprising: administering a therapeutically effectiveamount of acetyl-leucine or a pharmaceutically acceptable salt thereofto the subject, wherein the subject is asymptomatic.
 37. The methodaccording to claim 36, wherein the subject has been found to have agenetic and/or biochemical marker of the neurodegenerative disease. 38.A method of delaying onset of a neurodegenerative disease or one or moresymptoms of a neurodegenerative disease that would otherwise be expectedto manifest according to typical disease progression in a subject inneed thereof comprising: administering a therapeutically effectiveamount of acetyl-leucine or a pharmaceutically acceptable salt thereofto the subject.
 39. A method of treating a neurodegenerative disease orone or more symptoms associated with a neurodegenerative disease in asubject in need thereof comprising: administering a therapeuticallyeffective amount of the acetyl-leucine or a pharmaceutically acceptablesalt thereof to the subject for a duration chosen from at least about 3months, at least about 6 months, at least about 1 year, at least about 2years, and at least about 5 years.
 40. A method of delaying progressionof a neurodegenerative disease or one or more symptoms associated with aneurodegenerative disease in a subject in need thereof over time ascompared to typical disease progression comprising: administering atherapeutically effective amount of the acetyl-leucine or apharmaceutically acceptable salt thereof to the subject for a durationchosen from at least about 3 months, at least about 6 months, at leastabout 1 year, at least about 2 years, and at least about 5 years.
 41. Amethod of reversing progression of a neurodegenerative disease or one ormore symptoms associated with a neurodegenerative disease over time in asubject in need thereof comprising: administering a therapeuticallyeffective amount of the acetyl-leucine or a pharmaceutically acceptablesalt thereof to the subject for a duration chosen from at least about 3months, at least about 6 months, at least about 1 year, at least about 2years, and at least about 5 years.
 42. A method of improving in asubject in need thereof a biochemical marker of a neurodegenerativedisease over time comprising: administering a therapeutically effectiveamount of the acetyl-leucine or a pharmaceutically acceptable saltthereof to the subject for a duration chosen from at least about 3months, at least about 6 months, at least about 1 year, at least about 2years, and at least about 5 years.
 43. The method according to claim 42,wherein the biochemical marker is increased lysosomal volume.
 44. Themethod according to claim 30, wherein the method comprises initiatingadministration of a therapeutically effective amount of acetyl-leucineor a pharmaceutically acceptable salt thereof to the subject in needthereof when the subject is asymptomatic.
 45. The method according toclaim 44, wherein the initial administration occurs after the subjecthas been found to have a genetic and/or biochemical marker of theneurodegenerative disease.
 46. The method according to claim 30, whereinthe method comprises administering a therapeutically effective amount ofthe acetyl-leucine or a pharmaceutically acceptable salt thereof to thesubject for a duration chosen from at least about 3 months, at leastabout 6 months, at least about 1 year, at least about 2 years, and atleast about 5 years.
 47. The method according to claim 30, wherein theacetyl-leucine is acetyl-DL-leucine.
 48. The method according to claim30, wherein the acetyl-leucine has an enantiomeric excess of theL-enantiomer or the D-enantiomer.
 49. The method according to claim 30,wherein therapeutically effect amount of from about 1 g to about 15 gper day, from about 1 g to about 10 g per day, from about 1.5 g to about7 g per day, from about 4 g to about 6 g per day, or from about 4 g toabout 5 g per day.
 50. The method according to claim 36, wherein theneurodegenerative disease is associated with lysosomal dysfunction. 51.The method according to claim 50, wherein the neurodegenerative diseaseassociated with lysosomal dysfunction is chosen from alcoholism,Alzheimer's disease, amyotrophic lateral sclerosis (ALS), Canavandisease, frontotemporal lobar degeneration, Huntington's disease,multiple system atrophy (MSA-P/MSA-C), multiple sclerosis, narcolepsy,Parkinson's Disease, Smith Lemli Opitz Syndrome (SLOS) (an inborn errorof cholesterol synthesis), Tangier disease, Pelizaeus-MerzbacherDisease, Pick's disease, frontotemporal dementia with parkinsonism,prion diseases, progressive supranuclear palsy, spinal muscular atrophy,neurodegenerative lysosomal storage disorders (LSDs), SpinocerebellarAtaxia (SCA) 1, Spinocerebellar Ataxia (SCA) 2, Spinocerebellar Ataxia(SCA) 3 (Machado-Joseph disease), Spinocerebellar Ataxia (SCA) 6,Spinocerebellar Ataxia (SCA) 7, Spinocerebellar Ataxia (SCA) 17,dentatorubral-pallidoluysian atrophy, Autosomal Recessive Spastic Ataxiaof Charlevoix-Saguenay (ARSACS), autosomal recessive cerebellar ataxiatype 1 (Recessive Ataxia of Beauce (RAB), SYNE-1 mutation), autosomalrecessive cerebellar ataxia type 2 (spinocerebellar ataxia autosomalrecessive 9, SCAR9), ataxia with vitamin E deficiency (AVED), ataxiatelangiectasia (Louis Barr disease), Freidreich's ataxia (FRDA), andataxia with coenzyme Q10 deficiency.
 52. The method according to claim51, wherein the neurodegenerative disease associated with lysosomaldysfunction is chosen from ALS, MSA-P, MSA-C, frontotemporal dementiawith parkinsonism, progressive supranuclear palsy, Alzheimer's disease,SCA 1, and ataxia telangiectasia.
 53. The method according to claim 36,wherein the neurodegenerative disease is chosen from Alexander'sdisease, Alper's disease, cerebral palsy, Cockayne syndrome,corticobasal degeneration, HIV-associated dementia, Kennedy's disease,neuroborreliosis, primary lateral sclerosis, Refsum's disease,Schilder's disease, subacute combined degeneration of spinal cordsecondary to pernicious anaemia, hereditary motor and sensory neuropathywith proximal dominance, Wobbly Hedgehog Syndrome (WHS), progressivemuscular atrophy (Duchenne-Aran muscular atrophy), progressive bulbarpalsy, pseudobulbar palsy, HIV-associated neurocognitive disorders(HAND), Vascular Parkinsonism, lower body Parkinson's syndrome,cerebellar ataxia, and cerebellar downbeat nystagmus.
 54. The methodaccording to claim 36, wherein the neurodegenerative disease is a MotorNeuron Disease.
 55. A method of reducing the severity of aneurodegenerative disease or reducing the severity of or eliminating oneor more existing symptoms associated with a neurodegenerative disease ina subject in need thereof comprising: administering a therapeuticallyeffective amount of acetyl-leucine or a pharmaceutically acceptable saltthereof to the subject, wherein the neurodegenerative disease is notcerebellar ataxia or Niemann-Pick Type C.
 56. A method of providingneuroprotection in a subject having, suspected of having, or at risk ofhaving a neurodegenerative disease comprising: administering atherapeutically effective amount of acetyl-leucine or a pharmaceuticallyacceptable salt thereof to the subject for a duration chosen from atleast about 3 months, at least about 6 months, at least about 1 year, atleast about 2 years, and at least about 5 years.
 57. The methodaccording to claim 36, wherein the neurodegenerative disease is chosenfrom ALS, MSA-P, MSA-C, frontotemporal dementia with parkinsonism,progressive supranuclear palsy, Alzheimer's disease, SCA 1, ataxiatelangiectasia, cerebellar downbeat nystagmus, SCA 28, ataxia withoculomotor apraxia type 4 (AOA4), Lewy Body dementia, and corticobasaldegeneration.